Re: Normal Fungal Ecology

[Guest guest]

,

As always you bring up some interesting points. However, in the non-viable

state where spores can be dead or fragmented, the allergens and histamines produced,

are as much if not more of an asthma/allergen problem to susceptible persons than

are live organisms. Care to comment?

Moffett

 

From:

iequality [mailto:iequality ] On Behalf Of

Shane

Sent: Friday, August 24, 2007 4:24 AM

To: iequality

Subject: Re: Normal Fungal Ecology

,

Thank you for making my point. You can't have the

study of ecology without living organisms. LOTS of the biology that is measured

is dead and/or we don't care if they are.

AND, show my anyone who can assess the mold, bacteria, algae

and insects correctly (your list is way short, btw). We at best do aerobiology,

NOT fungal ecology.

Thinking you are broad-minded does not make reality. Again,

you are NOT doing ecology when you try and measure some of the things, both

dead and alive, in a house or building.

•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

D. Shane, Ph.D.

:

Respectfully disagree. My understanding/definition

of ECOLOGY is: The study of how organisms interact with each other and their

physical environment.

Yes.....what many folks are trying to accomplish

is more akin to determining the distribution of fungal spores, but for us that

are a bit more broad minded, and looking beyond the spore count, fungal ecology

makes sense. This said, I don’t use the term, but I am trying to

understand the ecology when I am assessing biologicals (e.g., molds, bacteria,

algaes, insects, etc.)

On 8/23/07 4:38 AM, " Shane "

wrote:

What is this talk about Ecology? I submit that

there is NOT a person on this list capable of speaking about fungal ecology.

What I am hearing is NOT fungal ecology, but rather the distribution of fungi,

however poorly defined, identified on building surfaces. This is NOT ecology,

but a product of the fungal ecology surrounding the building. No fungus ever

evolved to live in a building. It is fortuitous that fungi are present in and

on buildings.

One of the reasons that looking at fungi in

buildings is NOT fungal ecology is simply because many that we identify are NOT

living. That is a lot of NOT's :-)

This may be a fine point, but I bring it up to

corral this group, so we understand our limitations and NOT take on air of

erudition we do NOT have and cannot possibly attain.

Fungi in buildings, is I admit, a sometimes

nebulous, moving target, and hard to pigeon hole. But let us use terms

correctly and understand them fully before we voice opinions about them.

I often feel, when I hear this kind of talk, e.g.,

fungal ecology, that it is like a person who watches a lot of nature on TV.

They seem to be very knowledgeable about the subject, but are quite lacking

when asked about relationships, distributions, etc. That is, the detail a

person would have who really knows what the subject is and has studied it. The

detail necessary to make intelligent comments and back them up with data.

I apologize if these comments seems harsh. They

are meant to be dispassionate observations. When we increase our education

and elevate our understanding, we can command a higher standard of all of

those around us, including the organizations that govern the industry.

•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

D. Shane, Ph.D.

Normal

fungal ecology depends on the environment. It is different for:

Clean rooms,

Hospitals,

Total Brick/Masonry/Steel and glass buildings

Wood frame structures

Building without AC that leave windows open

Building on tropical islands.

Building in warm and humid climates (especially

with dewpoints about

60°F

Crawlspaces or other spaces that are open to dirt,

variable depending

upon soil moisture

Buildings in desert climates

Level of air filtration in the environment

and so on.

The issue here is one where the IEPs have

to estimate what they believe

is the normal fungal ecology for these

different buildings and circumstances.

There are a number of studies in the literature

that claim to look at

normal fungal ecology. However, they do not take

into account building

type, climate, etc.

>From a remediation viewpoint, if one

picks very low numbers for PRV,

you will most likely be below

the normal fungal ecology for most environments.

>From a genera viewpoint, the most

common genera should be Clado. This

is the most common genera worldwide. It should be

the predominant

genera in most cases, but this can vary depending

on how low the levels

are.

We use " control areas " that are

not affected by water intrusion

problems as a potential way of assessing the

normal fungal ecology in a

particular building. This is not always a perfect

measure but it can

be useful. However, in many cases the whole

building is affected and

no control area exists. This is where literature

references can be

cited.

Normal fungal ecology does exist. Just

because no certification body

has put numbers to this concept for various

environments does not

negate its existence.

Bob s

[Guest guest]

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Bob s wrote: "So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology."

Bob,

I understand very well what you are saying and have no disagreement with the fact that mold can and does grow indoors and on building materials when there is moisture present. I also don't disagree that it is "normal" in a statistical sense for any given house to have indoor mold growth occurring somewhere.

The problem I have is with the IICRC definition (or lack thereof) of their term "normal fungal ecology" in the context of an environmental assessment and how decisions are to be made by an IEP based on their term "Conditon 1". It essentially means that, for those "normal" indoor growth issues you raised, no remediation would be indicated because it is normal. Or worse, the definition of Condition 1 can be used to say that the levels of spores are "normal", therefore further remediation is not necessary.

I am not arguing that it isn't normal for some mold growth to occur in a given structure at some point in time. Or that potted plants, or dogs going in and out, don't contribute to mold spores being present indoors normally. I'm saying that indoor mold growth does not meet the strict definition of fungal ecology (organisms competing against one another in their ecological niches as Shane discussed) unless the house is composting. And I am saying that it is not REALLY "normal", since visible mold growth in indoor environments is unacceptable and is an indication of a moisture problem.

So, even if I agree in principle that normal fungal ecology exists in an indoor environment to the extent that it is normal for it to get wet (where that might be normal), I still don't agree that it should be considered Condition 1 for decision-making purposes. If you can identify how and why mold growth occurs indoors for the reasons you listed, and many others, why isn't this indoor growth considered Condition 3 or Condition 2? And if it is Condition 3 or Condition 2, it isn't normal fungal ecology by IICRC definition.

It is the IICRC definition of "normal fungal ecology" and Condition 1 that is confusing, not that mold grows in buildings for the reasons you have discussed. Normal implies acceptable. Indoor fungal growth should only be considered normal if it is acceptable. It is hard to make the case that indoor growth is acceptable, no matter how normal it might be.

Steve Temes

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Bob s wrote: "So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology."

Bob,

I understand very well what you are saying and have no disagreement with the fact that mold can and does grow indoors and on building materials when there is moisture present. I also don't disagree that it is "normal" in a statistical sense for any given house to have indoor mold growth occurring somewhere.

The problem I have is with the IICRC definition (or lack thereof) of their term "normal fungal ecology" in the context of an environmental assessment and how decisions are to be made by an IEP based on their term "Conditon 1". It essentially means that, for those "normal" indoor growth issues you raised, no remediation would be indicated because it is normal. Or worse, the definition of Condition 1 can be used to say that the levels of spores are "normal", therefore further remediation is not necessary.

I am not arguing that it isn't normal for some mold growth to occur in a given structure at some point in time. Or that potted plants, or dogs going in and out, don't contribute to mold spores being present indoors normally. I'm saying that indoor mold growth does not meet the strict definition of fungal ecology (organisms competing against one another in their ecological niches as Shane discussed) unless the house is composting. And I am saying that it is not REALLY "normal", since visible mold growth in indoor environments is unacceptable and is an indication of a moisture problem.

So, even if I agree in principle that normal fungal ecology exists in an indoor environment to the extent that it is normal for it to get wet (where that might be normal), I still don't agree that it should be considered Condition 1 for decision-making purposes. If you can identify how and why mold growth occurs indoors for the reasons you listed, and many others, why isn't this indoor growth considered Condition 3 or Condition 2? And if it is Condition 3 or Condition 2, it isn't normal fungal ecology by IICRC definition.

It is the IICRC definition of "normal fungal ecology" and Condition 1 that is confusing, not that mold grows in buildings for the reasons you have discussed. Normal implies acceptable. Indoor fungal growth should only be considered normal if it is acceptable. It is hard to make the case that indoor growth is acceptable, no matter how normal it might be.

Steve Temes

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

I guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological componentto building mold, but I stop there. Discovering mold growth in a home is normal, not ecology."1. The most common mold species worldwide is Clado. You can find a level of clado in all buildings."Here again you miss the point because you are not a mycologist nor even a biologist. Cladosporium is NOT a species. It is a GENUS.When you look at species level the picture gets LOTS more complex. Almost nobody is looking or noting the species level. "What is the most common bug in homes? Does the bug represent the majority of bugs in a home? What about building infestations. They spread much further than mold spores. Bugs simply are not evenly distributed world wide. Clado, alternaria and pen are."I don't know where you get your information here. Bugs spreading much further in a home than fungi?That is a big no. Where you have bugs you have fungi. Both from the air, and the bugs bringing them themselves for a variety of reasons.Don't forget, the fungi are predatory on the bugs themselves along with LOTS more intricate interactions. So, this statement is justmade up. "This is not to say, that total number of species of bugs exceeds that of the total number of species of mold. But, I am not talking about species that have low probabilities. Sure you can find one spore of this or that. But that is not significant, in my opinion."One spore being not significant. That may be true, but have you ever seen only one spore in a home? I think not. "What is of interest is what can one expect to find "normally" in any home that is climate controlled. Since mold spores are spread worldwide by the atmosphere, there is a more common genera distribution."Fungal spores are spread by the atmosphere and this is common around the world. Fungal spores don't have a worldwide distribution becausethey are spread by the wind. There are some long rangers, but they are far from going worldwide. Now this is ecology. "As for bacteria, SA is very common, but MRSA is also speading. The current LA prison outbreak is a very good example. What bacteria is the most predominant? We can't easily speciate bacteria without extensive costs and time - and the results are highly variable. And exactly what do they mean?"Bacteria is a very interesting part of the picture. However, we don't "speciate". That is an evolutionary process. Everyone should stop using this term.It is incorrect, just as "Pollens" is incorrect. Please say something like, "we need to identify the species of bacteria...." Just a fine point, but important.Also, you are dead right with the bacteria problem. They cause a lot of problems for us. However, the bacteria are also a large problem that we have very littleto say about. Did you know that we have identified less than 1/2 of all the bacteria species in the human gut? And that is right at home. This fact has lots ofimplications for asthma, allergy, and general health. "This gets back to mold, my experience and the almost 1,000 papers I have read on this subject - from the last 150 years, shows typical mold genera to be much less variable than bugs or bacteria."Bob, I didn't know you were 150 years old:-) (just kidding)! Did you think that 1,000 papers was a lot? What percentage of those are from mycologyjournals? I'll bet not many related to ecology. Again, the fungi are less variable than the other things because of the way and the length of time we have looked.When you filter what you look for, you will always get a smaller subset of the whole. It is true, however, that the insects are the most diverse form of life that weknow of. I am not just trying to be a stone around everyone's neck, but I feel that it is important to not overstate what we know. We still need to be discovering in this nascent scienceand excluding things on little evidence is not good. We know almost nothing about building fungi and mold. The list of fungi and mold that I have seen in buildingsis very long. Every time I look for something new, I find something new. Lots of unknown species also. In fact, there many more things that I don't know about this subject than I know.I sometimes feel like what Mark Twain said about the science (regarding evolution of man), "If we continue to study it, we will soon know nothing about it".He also said something like, "...science, with such little evidence can  give us such wholesale conclusions"! Twain also stated, "It's a terrible death to be talked to death"I applaud the efforts in trying to understand this issue(s). I am NOT trying to be  contentious, really.Steve,You bring up a good question as to whether it is normal to have some mold growth in a home?The answer to this question, in most respects, is dependent upon what are the climatic norms for the location of the home and what is the home made of?For example, in warm southern climates and the tropics, you will find relative humidity levels that are above 80% RH for extended periods of time. We are not talking hours here, we are talking about days, weeks, or many months.If you present wood, paper, drywall, etc to these climatic conditions, they will grow mold. The growth may be very slow and in many cases may not be visible for a few years, but it will be there.The spanish knew this problem and hence built their buildings out of stone with plaster (lime) finishes. (also note the high pH that would minimize mold growth, but only until it got dirty.)As you move to northerly climates, the time that this level of humidity is present decreases, but it does not go away until you get to either deserts or extreme arctic condition. (Summers are very humid up in Canada and so is the wet soil.)During these climate conditions, normal mold growth, will occur in a building.Sure we can try to air condition, and dry out the interior portions, to minimize elevated RH, but we do not condition every surface of the exterior walls. Hence, some growth will eventually occur in the exterior walls. Just look at old buildings. Even 100 year old stone exteriors, will have some mold on the old 2 x 4 wall studs.A more recent area of the home where extend elevated moisture levels are now found are showers. Years ago, when buildings leaked more, you did not build up as much RH in bathrooms. But today, with much less air infiltration, and people who don't use their bath exhaust fans, you get mold in showers. The number of mold 'killing' bathroom chemicals has significantly increased in the last 10 years.This is another normal area where mold and other microbes can always be found growing in homes. This area is the drain pipes right above the P traps and inside of garbage disposals and in the overflow space in sinks. (Yes, I have smelled a few sink over flow holes in my days-that have turned out to be the problem.) Sometimes you can actually smell this mold and bacteria growth in poor ventilated bathrooms.Lastly, basements have a very high potential for elevated RH. There has been considerable discussion about crawl spaces (on the list) recently and what to do with them. Basements are tall crawl spaces with concrete floors. The water vapor below the concrete (w/o a vapor retarder or a disintegrated VB) will diffuse into the basement concrete floor and present elevated moisture levels - below tile or any other moisture barrier on the floor. (except in deserts-most of the time). Put carpeting on these concrete floors and you grow mold, bacteria etc. (putting in radon type sub slab ventilation can really minimize this problem.- but at an energy cost.)So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology.Bob

[Guest guest]

I guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological componentto building mold, but I stop there. Discovering mold growth in a home is normal, not ecology."1. The most common mold species worldwide is Clado. You can find a level of clado in all buildings."Here again you miss the point because you are not a mycologist nor even a biologist. Cladosporium is NOT a species. It is a GENUS.When you look at species level the picture gets LOTS more complex. Almost nobody is looking or noting the species level. "What is the most common bug in homes? Does the bug represent the majority of bugs in a home? What about building infestations. They spread much further than mold spores. Bugs simply are not evenly distributed world wide. Clado, alternaria and pen are."I don't know where you get your information here. Bugs spreading much further in a home than fungi?That is a big no. Where you have bugs you have fungi. Both from the air, and the bugs bringing them themselves for a variety of reasons.Don't forget, the fungi are predatory on the bugs themselves along with LOTS more intricate interactions. So, this statement is justmade up. "This is not to say, that total number of species of bugs exceeds that of the total number of species of mold. But, I am not talking about species that have low probabilities. Sure you can find one spore of this or that. But that is not significant, in my opinion."One spore being not significant. That may be true, but have you ever seen only one spore in a home? I think not. "What is of interest is what can one expect to find "normally" in any home that is climate controlled. Since mold spores are spread worldwide by the atmosphere, there is a more common genera distribution."Fungal spores are spread by the atmosphere and this is common around the world. Fungal spores don't have a worldwide distribution becausethey are spread by the wind. There are some long rangers, but they are far from going worldwide. Now this is ecology. "As for bacteria, SA is very common, but MRSA is also speading. The current LA prison outbreak is a very good example. What bacteria is the most predominant? We can't easily speciate bacteria without extensive costs and time - and the results are highly variable. And exactly what do they mean?"Bacteria is a very interesting part of the picture. However, we don't "speciate". That is an evolutionary process. Everyone should stop using this term.It is incorrect, just as "Pollens" is incorrect. Please say something like, "we need to identify the species of bacteria...." Just a fine point, but important.Also, you are dead right with the bacteria problem. They cause a lot of problems for us. However, the bacteria are also a large problem that we have very littleto say about. Did you know that we have identified less than 1/2 of all the bacteria species in the human gut? And that is right at home. This fact has lots ofimplications for asthma, allergy, and general health. "This gets back to mold, my experience and the almost 1,000 papers I have read on this subject - from the last 150 years, shows typical mold genera to be much less variable than bugs or bacteria."Bob, I didn't know you were 150 years old:-) (just kidding)! Did you think that 1,000 papers was a lot? What percentage of those are from mycologyjournals? I'll bet not many related to ecology. Again, the fungi are less variable than the other things because of the way and the length of time we have looked.When you filter what you look for, you will always get a smaller subset of the whole. It is true, however, that the insects are the most diverse form of life that weknow of. I am not just trying to be a stone around everyone's neck, but I feel that it is important to not overstate what we know. We still need to be discovering in this nascent scienceand excluding things on little evidence is not good. We know almost nothing about building fungi and mold. The list of fungi and mold that I have seen in buildingsis very long. Every time I look for something new, I find something new. Lots of unknown species also. In fact, there many more things that I don't know about this subject than I know.I sometimes feel like what Mark Twain said about the science (regarding evolution of man), "If we continue to study it, we will soon know nothing about it".He also said something like, "...science, with such little evidence can  give us such wholesale conclusions"! Twain also stated, "It's a terrible death to be talked to death"I applaud the efforts in trying to understand this issue(s). I am NOT trying to be  contentious, really.Steve,You bring up a good question as to whether it is normal to have some mold growth in a home?The answer to this question, in most respects, is dependent upon what are the climatic norms for the location of the home and what is the home made of?For example, in warm southern climates and the tropics, you will find relative humidity levels that are above 80% RH for extended periods of time. We are not talking hours here, we are talking about days, weeks, or many months.If you present wood, paper, drywall, etc to these climatic conditions, they will grow mold. The growth may be very slow and in many cases may not be visible for a few years, but it will be there.The spanish knew this problem and hence built their buildings out of stone with plaster (lime) finishes. (also note the high pH that would minimize mold growth, but only until it got dirty.)As you move to northerly climates, the time that this level of humidity is present decreases, but it does not go away until you get to either deserts or extreme arctic condition. (Summers are very humid up in Canada and so is the wet soil.)During these climate conditions, normal mold growth, will occur in a building.Sure we can try to air condition, and dry out the interior portions, to minimize elevated RH, but we do not condition every surface of the exterior walls. Hence, some growth will eventually occur in the exterior walls. Just look at old buildings. Even 100 year old stone exteriors, will have some mold on the old 2 x 4 wall studs.A more recent area of the home where extend elevated moisture levels are now found are showers. Years ago, when buildings leaked more, you did not build up as much RH in bathrooms. But today, with much less air infiltration, and people who don't use their bath exhaust fans, you get mold in showers. The number of mold 'killing' bathroom chemicals has significantly increased in the last 10 years.This is another normal area where mold and other microbes can always be found growing in homes. This area is the drain pipes right above the P traps and inside of garbage disposals and in the overflow space in sinks. (Yes, I have smelled a few sink over flow holes in my days-that have turned out to be the problem.) Sometimes you can actually smell this mold and bacteria growth in poor ventilated bathrooms.Lastly, basements have a very high potential for elevated RH. There has been considerable discussion about crawl spaces (on the list) recently and what to do with them. Basements are tall crawl spaces with concrete floors. The water vapor below the concrete (w/o a vapor retarder or a disintegrated VB) will diffuse into the basement concrete floor and present elevated moisture levels - below tile or any other moisture barrier on the floor. (except in deserts-most of the time). Put carpeting on these concrete floors and you grow mold, bacteria etc. (putting in radon type sub slab ventilation can really minimize this problem.- but at an energy cost.)So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology.Bob

[Guest guest]

Bob B,

IMHO I think the question to ask might be:

Do we presently and/or did we in the years past design and build these

buildings with the intent of desired and/or expected growth? Furthermore, as

stated in your post, the builders of yesterday utilized different building

materials to avoid unintended growth. Knowing the builders of yesterday altered

the building practices to avoid growth, they likewise must have realized growth

related to negative health impacts upon the occupant.

Otherwise if mold was an expected design what

was the expected benefit? What were the expected levels? What were the expected

thresholds of that would create harm to the occupants and what engineering

controls were set in place to controls these levels. I do not believe “expected”

growth was an intended end.

If not, than we can begin to establish an expected

ecology (no mold growth was consider or intended) during the design phase. Notice

I did not remove ignorance of what may contribute to mold growth only that mold

growth was not an “intended” desire during the design phase of the

building.

Now whither the intended design

demonstrated the expected end (absence of growth) may be another story as evidenced

by the ever morphing building designs. Regardless of the flawed designs and/or mechanical

obsolescence the intended design and/or intended indoor building ecology may

have the greater factor as determining what the normal expected levels would

be.

I guess we must determine if “normal”

equates to “normally flawed.” And does normally flawed allow the

bar to be lowered. In my opinion understanding that building were and are

designed with the occupant’s health and comfort in mind, I do not expect

mold growth to be a designed expectation and therefore I look at the expected

levels to be below background based on outside conditions.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Bob s

Sent: Sunday, August 26, 2007 9:11

AM

To: iequality

Subject: Re: Normal

Fungal Ecology

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada

and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Bob, Steve and All,

Can we agree that we need to select a better description?

Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly designed, well maintained buildings.

Mold may grow in dirty showers, but a lot of effort goes into stopping it and cleaning it out.

Yeast and slim molds in waste water pipes is not a big deal in a properly designed system.

If the garbage disposal is stinking with microbial growth, don't normal, educated occupants clean it with one of the dozen products on the market designed to kill unwanted biological growth in the garbage disposal?

Bob B, where do you stop?

Lets try to start with "On a site specific basis, in a properly designed, well maintained building, without a history of unremediated moisture problems; there is an expected level of fungal components in the air and on surfaces in settled dust. The fungal components can originate from a number of sources and change rapidly based upon source loading factors and building design and operation. For example, fungal components may originate from the outdoor air, occupant activities, house plants, and other deminimus wet areas in the building such as toilets and drain pipes. Geographic regions with extended periods of high relative humidity will typically have the potential for higher indoor fungal levels, however, frequency of cleaning and the level of mechanical air filtration and dehumidification will influence the actual level of fungal components typically found in the indoor environment on a site specific basis".

Lets all try to make a better definition, and I don't care how long it is, so long as it makes sense and is correct.

Bradley HarrSr. Environmental Scientist

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of ShaneSent: Tuesday, August 28, 2007 5:53 AMTo: iequality Subject: Re: Normal Fungal Ecology

I guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological component

to building mold, but I stop there. Discovering mold growth in a home is normal, not ecology.

"1. The most common mold species worldwide is Clado. You can find a level of clado in all buildings."

Here again you miss the point because you are not a mycologist nor even a biologist. Cladosporium is NOT a species. It is a GENUS.

When you look at species level the picture gets LOTS more complex. Almost nobody is looking or noting the species level.

"What is the most common bug in homes? Does the bug represent the majority of bugs in a home? What about building infestations. They spread much further than mold spores. Bugs simply are not evenly distributed world wide. Clado, alternaria and pen are."

I don't know where you get your information here. Bugs spreading much further in a home than fungi?

That is a big no. Where you have bugs you have fungi. Both from the air, and the bugs bringing them themselves for a variety of reasons.

Don't forget, the fungi are predatory on the bugs themselves along with LOTS more intricate interactions. So, this statement is just

made up."This is not to say, that total number of species of bugs exceeds that of the total number of species of mold.But, I am not talking about species that have low probabilities. Sure you can find one spore of this or that. But that is not significant, in my opinion."

One spore being not significant. That may be true, but have you ever seen only one spore in a home? I think not."What is of interest is what can one expect to find "normally" in any home that is climate controlled. Since mold spores are spread worldwide by the atmosphere, there is a more common genera distribution."

Fungal spores are spread by the atmosphere and this is common around the world. Fungal spores don't have a worldwide distribution because

they are spread by the wind. There are some long rangers, but they are far from going worldwide. Now this is ecology."As for bacteria, SA is very common, but MRSA is also speading. The current LA prison outbreak is a very good example. What bacteria is the most predominant? We can't easily speciate bacteria without extensive costs and time - and the results are highly variable. And exactly what do they mean?"

Bacteria is a very interesting part of the picture. However, we don't "speciate". That is an evolutionary process. Everyone should stop using this term.

It is incorrect, just as "Pollens" is incorrect. Please say something like, "we need to identify the species of bacteria...." Just a fine point, but important.

Also, you are dead right with the bacteria problem. They cause a lot of problems for us. However, the bacteria are also a large problem that we have very little

to say about. Did you know that we have identified less than 1/2 of all the bacteria species in the human gut? And that is right at home. This fact has lots of

implications for asthma, allergy, and general health.

"This gets back to mold, my experience and the almost 1,000 papers I have read on this subject - from the last 150 years, shows typical mold genera to be much less variable than bugs or bacteria."

Bob, I didn't know you were 150 years old:-) (just kidding)! Did you think that 1,000 papers was a lot? What percentage of those are from mycology

journals? I'll bet not many related to ecology. Again, the fungi are less variable than the other things because of the way and the length of time we have looked.

When you filter what you look for, you will always get a smaller subset of the whole. It is true, however, that the insects are the most diverse form of life that we

know of.

I am not just trying to be a stone around everyone's neck, but I feel that it is important to not overstate what we know. We still need to be discovering in this nascent science

and excluding things on little evidence is not good. We know almost nothing about building fungi and mold. The list of fungi and mold that I have seen in buildings

is very long. Every time I look for something new, I find something new. Lots of unknown species also. In fact, there many more things that I don't know about

this subject than I know.

I sometimes feel like what Mark Twain said about the science (regarding evolution of man), "If we continue to study it, we will soon know nothing about it".

He also said something like, "...science, with such little evidence can give us such wholesale conclusions"!

Twain also stated, "It's a terrible death to be talked to death"

I applaud the efforts in trying to understand this issue(s). I am NOT trying to be contentious, really.

Steve,You bring up a good question as to whether it is normal to have some mold growth in a home?The answer to this question, in most respects, is dependent upon what are the climatic norms for the location of the home and what is the home made of?For example, in warm southern climates and the tropics, you will find relative humidity levels that are above 80% RH for extended periods of time. We are not talking hours here, we are talking about days, weeks, or many months.If you present wood, paper, drywall, etc to these climatic conditions, they will grow mold. The growth may be very slow and in many cases may not be visible for a few years, but it will be there.The spanish knew this problem and hence built their buildings out of stone with plaster (lime) finishes. (also note the high pH that would minimize mold growth, but only until it got dirty.)As you move to northerly climates, the time that this level of humidity is present decreases, but it does not go away until you get to either deserts or extreme arctic condition. (Summers are very humid up in Canada and so is the wet soil.)During these climate conditions, normal mold growth, will occur in a building.Sure we can try to air condition, and dry out the interior portions, to minimize elevated RH, but we do not condition every surface of the exterior walls. Hence, some growth will eventually occur in the exterior walls. Just look at old buildings. Even 100 year old stone exteriors, will have some mold on the old 2 x 4 wall studs.A more recent area of the home where extend elevated moisture levels are now found are showers. Years ago, when buildings leaked more, you did not build up as much RH in bathrooms. But today, with much less air infiltration, and people who don't use their bath exhaust fans, you get mold in showers. The number of mold 'killing' bathroom chemicals has significantly increased in the last 10 years.This is another normal area where mold and other microbes can always be found growing in homes. This area is the drain pipes right above the P traps and inside of garbage disposals and in the overflow space in sinks. (Yes, I have smelled a few sink over flow holes in my days-that have turned out to be the problem.) Sometimes you can actually smell this mold and bacteria growth in poor ventilated bathrooms.Lastly, basements have a very high potential for elevated RH. There has been considerable discussion about crawl spaces (on the list) recently and what to do with them. Basements are tall crawl spaces with concrete floors. The water vapor below the concrete (w/o a vapor retarder or a disintegrated VB) will diffuse into the basement concrete floor and present elevated moisture levels - below tile or any other moisture barrier on the floor. (except in deserts-most of the time). Put carpeting on these concrete floors and you grow mold, bacteria etc. (putting in radon type sub slab ventilation can really minimize this problem.- but at an energy cost.)So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology.Bob

[Guest guest]

Bob, Steve and All,

Can we agree that we need to select a better description?

Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly designed, well maintained buildings.

Mold may grow in dirty showers, but a lot of effort goes into stopping it and cleaning it out.

Yeast and slim molds in waste water pipes is not a big deal in a properly designed system.

If the garbage disposal is stinking with microbial growth, don't normal, educated occupants clean it with one of the dozen products on the market designed to kill unwanted biological growth in the garbage disposal?

Bob B, where do you stop?

Lets try to start with "On a site specific basis, in a properly designed, well maintained building, without a history of unremediated moisture problems; there is an expected level of fungal components in the air and on surfaces in settled dust. The fungal components can originate from a number of sources and change rapidly based upon source loading factors and building design and operation. For example, fungal components may originate from the outdoor air, occupant activities, house plants, and other deminimus wet areas in the building such as toilets and drain pipes. Geographic regions with extended periods of high relative humidity will typically have the potential for higher indoor fungal levels, however, frequency of cleaning and the level of mechanical air filtration and dehumidification will influence the actual level of fungal components typically found in the indoor environment on a site specific basis".

Lets all try to make a better definition, and I don't care how long it is, so long as it makes sense and is correct.

Bradley HarrSr. Environmental Scientist

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of ShaneSent: Tuesday, August 28, 2007 5:53 AMTo: iequality Subject: Re: Normal Fungal Ecology

I guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological component

to building mold, but I stop there. Discovering mold growth in a home is normal, not ecology.

"1. The most common mold species worldwide is Clado. You can find a level of clado in all buildings."

Here again you miss the point because you are not a mycologist nor even a biologist. Cladosporium is NOT a species. It is a GENUS.

When you look at species level the picture gets LOTS more complex. Almost nobody is looking or noting the species level.

"What is the most common bug in homes? Does the bug represent the majority of bugs in a home? What about building infestations. They spread much further than mold spores. Bugs simply are not evenly distributed world wide. Clado, alternaria and pen are."

I don't know where you get your information here. Bugs spreading much further in a home than fungi?

That is a big no. Where you have bugs you have fungi. Both from the air, and the bugs bringing them themselves for a variety of reasons.

Don't forget, the fungi are predatory on the bugs themselves along with LOTS more intricate interactions. So, this statement is just

made up."This is not to say, that total number of species of bugs exceeds that of the total number of species of mold.But, I am not talking about species that have low probabilities. Sure you can find one spore of this or that. But that is not significant, in my opinion."

One spore being not significant. That may be true, but have you ever seen only one spore in a home? I think not."What is of interest is what can one expect to find "normally" in any home that is climate controlled. Since mold spores are spread worldwide by the atmosphere, there is a more common genera distribution."

Fungal spores are spread by the atmosphere and this is common around the world. Fungal spores don't have a worldwide distribution because

they are spread by the wind. There are some long rangers, but they are far from going worldwide. Now this is ecology."As for bacteria, SA is very common, but MRSA is also speading. The current LA prison outbreak is a very good example. What bacteria is the most predominant? We can't easily speciate bacteria without extensive costs and time - and the results are highly variable. And exactly what do they mean?"

Bacteria is a very interesting part of the picture. However, we don't "speciate". That is an evolutionary process. Everyone should stop using this term.

It is incorrect, just as "Pollens" is incorrect. Please say something like, "we need to identify the species of bacteria...." Just a fine point, but important.

Also, you are dead right with the bacteria problem. They cause a lot of problems for us. However, the bacteria are also a large problem that we have very little

to say about. Did you know that we have identified less than 1/2 of all the bacteria species in the human gut? And that is right at home. This fact has lots of

implications for asthma, allergy, and general health.

"This gets back to mold, my experience and the almost 1,000 papers I have read on this subject - from the last 150 years, shows typical mold genera to be much less variable than bugs or bacteria."

Bob, I didn't know you were 150 years old:-) (just kidding)! Did you think that 1,000 papers was a lot? What percentage of those are from mycology

journals? I'll bet not many related to ecology. Again, the fungi are less variable than the other things because of the way and the length of time we have looked.

When you filter what you look for, you will always get a smaller subset of the whole. It is true, however, that the insects are the most diverse form of life that we

know of.

I am not just trying to be a stone around everyone's neck, but I feel that it is important to not overstate what we know. We still need to be discovering in this nascent science

and excluding things on little evidence is not good. We know almost nothing about building fungi and mold. The list of fungi and mold that I have seen in buildings

is very long. Every time I look for something new, I find something new. Lots of unknown species also. In fact, there many more things that I don't know about

this subject than I know.

I sometimes feel like what Mark Twain said about the science (regarding evolution of man), "If we continue to study it, we will soon know nothing about it".

He also said something like, "...science, with such little evidence can give us such wholesale conclusions"!

Twain also stated, "It's a terrible death to be talked to death"

I applaud the efforts in trying to understand this issue(s). I am NOT trying to be contentious, really.

Steve,You bring up a good question as to whether it is normal to have some mold growth in a home?The answer to this question, in most respects, is dependent upon what are the climatic norms for the location of the home and what is the home made of?For example, in warm southern climates and the tropics, you will find relative humidity levels that are above 80% RH for extended periods of time. We are not talking hours here, we are talking about days, weeks, or many months.If you present wood, paper, drywall, etc to these climatic conditions, they will grow mold. The growth may be very slow and in many cases may not be visible for a few years, but it will be there.The spanish knew this problem and hence built their buildings out of stone with plaster (lime) finishes. (also note the high pH that would minimize mold growth, but only until it got dirty.)As you move to northerly climates, the time that this level of humidity is present decreases, but it does not go away until you get to either deserts or extreme arctic condition. (Summers are very humid up in Canada and so is the wet soil.)During these climate conditions, normal mold growth, will occur in a building.Sure we can try to air condition, and dry out the interior portions, to minimize elevated RH, but we do not condition every surface of the exterior walls. Hence, some growth will eventually occur in the exterior walls. Just look at old buildings. Even 100 year old stone exteriors, will have some mold on the old 2 x 4 wall studs.A more recent area of the home where extend elevated moisture levels are now found are showers. Years ago, when buildings leaked more, you did not build up as much RH in bathrooms. But today, with much less air infiltration, and people who don't use their bath exhaust fans, you get mold in showers. The number of mold 'killing' bathroom chemicals has significantly increased in the last 10 years.This is another normal area where mold and other microbes can always be found growing in homes. This area is the drain pipes right above the P traps and inside of garbage disposals and in the overflow space in sinks. (Yes, I have smelled a few sink over flow holes in my days-that have turned out to be the problem.) Sometimes you can actually smell this mold and bacteria growth in poor ventilated bathrooms.Lastly, basements have a very high potential for elevated RH. There has been considerable discussion about crawl spaces (on the list) recently and what to do with them. Basements are tall crawl spaces with concrete floors. The water vapor below the concrete (w/o a vapor retarder or a disintegrated VB) will diffuse into the basement concrete floor and present elevated moisture levels - below tile or any other moisture barrier on the floor. (except in deserts-most of the time). Put carpeting on these concrete floors and you grow mold, bacteria etc. (putting in radon type sub slab ventilation can really minimize this problem.- but at an energy cost.)So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology.Bob

[Guest guest]

Steve:

I too believe that there is a normal biological ecology in all structures; some more, some less. Take for example the hot humid Southeast, e.g., east Texas, Mississippi, and Georgia. Mold growth on surfaces in not uncommon and it can be very normal. Mitigating mold growth in bathrooms is a significant housekeeping chore in the southeast. Some folks are better at it than others, and some are fastidious about cleanliness. And what does it take to keep the mold a bay?.....lots and lots of caustic and potentially harmful chemicals! So which is worse and which is doing more harm? (A rhetorical question that does not warrant an answer.) Why not accept that some ecology is going to happen? Also, take for example the Pacific Northwest where leather goods (jackets, handbags, belts, etc.), will mold in your closet (nice white and green colonies too!); because closets typically have inadequate air flow and the air is cool and humid. Not much AC use in these climates. Normal is where normal is.

I for one, believe that some biology indoors is normal, it should be accepted as normal, and it should be a housekeeping issue – not representative of “contamination” as mentioned in IICRC’s S520. Drawing the line as to what is acceptable in your house, versus my house, versus Doe’s house, is the “crux of the biscuit” (to quote Zappa). Modern society has been lead to believe the Lysol commercials that the home should be free of germs, bacteria and mold, and be made to smell “Lysol fresh.” Choke!...Gasp!.....Yeah right!, and all the chemicals that go along with Lysol too. Does the IICRC do us a favor defining: normal fungal ecology,.....not sure, but it is a start. I sort of like Bob’s idea (it was Bob wasn’t it?), i.e., if it isn’t Condition 2 or Condition 3, then maybe it is: normal. Not perfect, but the idea has merit.

For what it is worth....

Bob s wrote: " So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology. "

Bob,

I understand very well what you are saying and have no disagreement with the fact that mold can and does grow indoors and on building materials when there is moisture present. I also don't disagree that it is " normal " in a statistical sense for any given house to have indoor mold growth occurring somewhere.

The problem I have is with the IICRC definition (or lack thereof) of their term " normal fungal ecology " in the context of an environmental assessment and how decisions are to be made by an IEP based on their term " Conditon 1 " . It essentially means that, for those " normal " indoor growth issues you raised, no remediation would be indicated because it is normal. Or worse, the definition of Condition 1 can be used to say that the levels of spores are " normal " , therefore further remediation is not necessary.

I am not arguing that it isn't normal for some mold growth to occur in a given structure at some point in time. Or that potted plants, or dogs going in and out, don't contribute to mold spores being present indoors normally. I'm saying that indoor mold growth does not meet the strict definition of fungal ecology (organisms competing against one another in their ecological niches as Shane discussed) unless the house is composting. And I am saying that it is not REALLY " normal " , since visible mold growth in indoor environments is unacceptable and is an indication of a moisture problem.

So, even if I agree in principle that normal fungal ecology exists in an indoor environment to the extent that it is normal for it to get wet (where that might be normal), I still don't agree that it should be considered Condition 1 for decision-making purposes. If you can identify how and why mold growth occurs indoors for the reasons you listed, and many others, why isn't this indoor growth considered Condition 3 or Condition 2? And if it is Condition 3 or Condition 2, it isn't normal fungal ecology by IICRC definition.

It is the IICRC definition of " normal fungal ecology " and Condition 1 that is confusing, not that mold grows in buildings for the reasons you have discussed. Normal implies acceptable. Indoor fungal growth should only be considered normal if it is acceptable. It is hard to make the case that indoor growth is acceptable, no matter how normal it might be.

Steve Temes

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Steve:

I too believe that there is a normal biological ecology in all structures; some more, some less. Take for example the hot humid Southeast, e.g., east Texas, Mississippi, and Georgia. Mold growth on surfaces in not uncommon and it can be very normal. Mitigating mold growth in bathrooms is a significant housekeeping chore in the southeast. Some folks are better at it than others, and some are fastidious about cleanliness. And what does it take to keep the mold a bay?.....lots and lots of caustic and potentially harmful chemicals! So which is worse and which is doing more harm? (A rhetorical question that does not warrant an answer.) Why not accept that some ecology is going to happen? Also, take for example the Pacific Northwest where leather goods (jackets, handbags, belts, etc.), will mold in your closet (nice white and green colonies too!); because closets typically have inadequate air flow and the air is cool and humid. Not much AC use in these climates. Normal is where normal is.

I for one, believe that some biology indoors is normal, it should be accepted as normal, and it should be a housekeeping issue – not representative of “contamination” as mentioned in IICRC’s S520. Drawing the line as to what is acceptable in your house, versus my house, versus Doe’s house, is the “crux of the biscuit” (to quote Zappa). Modern society has been lead to believe the Lysol commercials that the home should be free of germs, bacteria and mold, and be made to smell “Lysol fresh.” Choke!...Gasp!.....Yeah right!, and all the chemicals that go along with Lysol too. Does the IICRC do us a favor defining: normal fungal ecology,.....not sure, but it is a start. I sort of like Bob’s idea (it was Bob wasn’t it?), i.e., if it isn’t Condition 2 or Condition 3, then maybe it is: normal. Not perfect, but the idea has merit.

For what it is worth....

Bob s wrote: " So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology. "

Bob,

I understand very well what you are saying and have no disagreement with the fact that mold can and does grow indoors and on building materials when there is moisture present. I also don't disagree that it is " normal " in a statistical sense for any given house to have indoor mold growth occurring somewhere.

The problem I have is with the IICRC definition (or lack thereof) of their term " normal fungal ecology " in the context of an environmental assessment and how decisions are to be made by an IEP based on their term " Conditon 1 " . It essentially means that, for those " normal " indoor growth issues you raised, no remediation would be indicated because it is normal. Or worse, the definition of Condition 1 can be used to say that the levels of spores are " normal " , therefore further remediation is not necessary.

I am not arguing that it isn't normal for some mold growth to occur in a given structure at some point in time. Or that potted plants, or dogs going in and out, don't contribute to mold spores being present indoors normally. I'm saying that indoor mold growth does not meet the strict definition of fungal ecology (organisms competing against one another in their ecological niches as Shane discussed) unless the house is composting. And I am saying that it is not REALLY " normal " , since visible mold growth in indoor environments is unacceptable and is an indication of a moisture problem.

So, even if I agree in principle that normal fungal ecology exists in an indoor environment to the extent that it is normal for it to get wet (where that might be normal), I still don't agree that it should be considered Condition 1 for decision-making purposes. If you can identify how and why mold growth occurs indoors for the reasons you listed, and many others, why isn't this indoor growth considered Condition 3 or Condition 2? And if it is Condition 3 or Condition 2, it isn't normal fungal ecology by IICRC definition.

It is the IICRC definition of " normal fungal ecology " and Condition 1 that is confusing, not that mold grows in buildings for the reasons you have discussed. Normal implies acceptable. Indoor fungal growth should only be considered normal if it is acceptable. It is hard to make the case that indoor growth is acceptable, no matter how normal it might be.

Steve Temes

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Brad:

Wholeheartedly agree!

Tis why I use the term: reasonably anticipated trappings. I allows me flexibility to estimate a baseline which I believe is consistent with the hygiene of the site. If I walk into a relatively clean site, then I anticipate low trappings. If the site is dirty, then I can anticipate dirty trappings. I feel that any arbitrary fixed threshold is artificial and more often than not, unreasonable for a whole host of situations. I do not use the term: normal.

Bob, Steve and All,

Can we agree that we need to select a better description?

Let's stop using " normal fungal ecology " to describe fungal components in indoor air and dust in properly designed, well maintained buildings.

Mold may grow in dirty showers, but a lot of effort goes into stopping it and cleaning it out.

Yeast and slim molds in waste water pipes is not a big deal in a properly designed system.

If the garbage disposal is stinking with microbial growth, don't normal, educated occupants clean it with one of the dozen products on the market designed to kill unwanted biological growth in the garbage disposal?

Bob B, where do you stop?

Lets try to start with " On a site specific basis, in a properly designed, well maintained building, without a history of unremediated moisture problems; there is an expected level of fungal components in the air and on surfaces in settled dust. The fungal components can originate from a number of sources and change rapidly based upon source loading factors and building design and operation. For example, fungal components may originate from the outdoor air, occupant activities, house plants, and other deminimus wet areas in the building such as toilets and drain pipes. Geographic regions with extended periods of high relative humidity will typically have the potential for higher indoor fungal levels, however, frequency of cleaning and the level of mechanical air filtration and dehumidification will influence the actual level of fungal components typically found in the indoor environment on a site specific basis " .

Lets all try to make a better definition, and I don't care how long it is, so long as it makes sense and is correct.

Bradley Harr

Sr. Environmental Scientist

Re: Normal Fungal Ecology

I guess we will just have to disagree on this one guys. Perhaps we need a " settled dust " or " accumulated fungal flora " moniker for this thing. I agree that there certainly IS an ecological component

to building mold, but I stop there. Discovering mold growth in a home is normal, not ecology.

" 1. The most common mold species worldwide is Clado. You can find a

level of clado in all buildings. "

Here again you miss the point because you are not a mycologist nor even a biologist. Cladosporium is NOT a species. It is a GENUS.

When you look at species level the picture gets LOTS more complex. Almost nobody is looking or noting the species level.

" What is the most common bug in homes? Does the bug represent the

majority of bugs in a home? What about building infestations. They

spread much further than mold spores. Bugs simply are not evenly

distributed world wide. Clado, alternaria and pen are. "

I don't know where you get your information here. Bugs spreading much further in a home than fungi?

That is a big no. Where you have bugs you have fungi. Both from the air, and the bugs bringing them themselves for a variety of reasons.

Don't forget, the fungi are predatory on the bugs themselves along with LOTS more intricate interactions. So, this statement is just

made up.

" This is not to say, that total number of species of bugs exceeds that

of the total number of species of mold.

But, I am not talking about species that have low probabilities. Sure

you can find one spore of this or that. But that is not significant,

in my opinion. "

One spore being not significant. That may be true, but have you ever seen only one spore in a home? I think not.

" What is of interest is what can one expect to find " normally " in any

home that is climate controlled. Since mold spores are spread worldwide

by the atmosphere, there is a more common genera distribution. "

Fungal spores are spread by the atmosphere and this is common around the world. Fungal spores don't have a worldwide distribution because

they are spread by the wind. There are some long rangers, but they are far from going worldwide. Now this is ecology.

" As for bacteria, SA is very common, but MRSA is also speading. The

current LA prison outbreak is a very good example. What bacteria is

the most predominant? We can't easily speciate bacteria without

extensive costs and time - and the results are highly variable. And

exactly what do they mean? "

Bacteria is a very interesting part of the picture. However, we don't " speciate " . That is an evolutionary process. Everyone should stop using this term.

It is incorrect, just as " Pollens " is incorrect. Please say something like, " we need to identify the species of bacteria.... " Just a fine point, but important.

Also, you are dead right with the bacteria problem. They cause a lot of problems for us. However, the bacteria are also a large problem that we have very little

to say about. Did you know that we have identified less than 1/2 of all the bacteria species in the human gut? And that is right at home. This fact has lots of

implications for asthma, allergy, and general health.

" This gets back to mold, my experience and the almost 1,000 papers I

have read on this subject - from the last 150 years, shows typical mold

genera to be much less variable than bugs or bacteria. "

Bob, I didn't know you were 150 years old:-) (just kidding)! Did you think that 1,000 papers was a lot? What percentage of those are from mycology

journals? I'll bet not many related to ecology. Again, the fungi are less variable than the other things because of the way and the length of time we have looked.

When you filter what you look for, you will always get a smaller subset of the whole. It is true, however, that the insects are the most diverse form of life that we

know of.

I am not just trying to be a stone around everyone's neck, but I feel that it is important to not overstate what we know. We still need to be discovering in this nascent science

and excluding things on little evidence is not good. We know almost nothing about building fungi and mold. The list of fungi and mold that I have seen in buildings

is very long. Every time I look for something new, I find something new. Lots of unknown species also. In fact, there many more things that I don't know about

this subject than I know.

I sometimes feel like what Mark Twain said about the science (regarding evolution of man), " If we continue to study it, we will soon know nothing about it " .

He also said something like, " ...science, with such little evidence can give us such wholesale conclusions " !

Twain also stated, " It's a terrible death to be talked to death "

I applaud the efforts in trying to understand this issue(s). I am NOT trying to be contentious, really.

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Bradley,

I concur with what you have said below. I

also agree that there will be a distribution of fungal components due to mice,

cats, dogs, shoes, and open doors and windows. Again you will notice I did not

say normal because what distributional impacts will each of these have and at what

ratio? Additionally, these distributions are not actual growth only distributions

of spores and/or particulate(s). Without playing on words, mold does not grow

in the air. Furthermore knowing fungi consumes its host, who would knowingly

build a building that would be decomposed by mold? What would the expected life

of the building be? We build them to avoid mold growth. So what is normal

growth? None, per intended design!!

Keep in mind here; so far the emphasis has

been on growth not particulate. And with a good cleaning, the particulate

should be removed and the expected results should be below background. Keep in

mind; unless it is snow covered the infiltrated air will migrate through the insulated

(filtered) wall thus the inside should be below the outside again unless the

door and windows are opened. So what is normal?

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Brad Harr

Sent: Tuesday, August 28, 2007

2:18 PM

To: iequality

Subject: RE: Normal

Fungal Ecology

Bob, Steve and All,

Can we agree that we need to select a better description?

Let's stop using " normal fungal

ecology " to describe fungal components in indoor air and dust in properly

designed, well maintained buildings.

Mold may grow in dirty showers, but a lot

of effort goes into stopping it and cleaning it out.

Yeast and slim molds in waste water pipes

is not a big deal in a properly designed system.

If the garbage disposal is stinking with

microbial growth, don't normal, educated occupants clean it with one of the dozen

products on the market designed to kill unwanted biological growth in the

garbage disposal?

Bob B, where do you stop?

Lets try to start with " On a site

specific basis, in a properly designed, well maintained building, without a

history of unremediated moisture problems; there is an expected level of fungal

components in the air and on surfaces in settled dust. The fungal

components can originate from a number of sources and change rapidly based

upon source loading factors and building design and operation. For

example, fungal components may originate from the outdoor air, occupant

activities, house plants, and other deminimus wet areas in the building such as

toilets and drain pipes. Geographic regions with extended periods of high

relative humidity will typically have the potential for higher indoor fungal

levels, however, frequency of cleaning and the level of mechanical air

filtration and dehumidification will influence the actual level of fungal

components typically found in the indoor environment on a site specific

basis " .

Lets all try to make a better definition,

and I don't care how long it is, so long as it makes sense and is

correct.

Bradley Harr

Sr. Environmental Scientist

Re: Normal

Fungal Ecology

I guess

we will just have to disagree on this one guys. Perhaps we need a " settled

dust " or " accumulated fungal flora " moniker for this thing. I

agree that there certainly IS an ecological component

to building mold, but I stop there. Discovering mold growth in a home

is normal, not ecology.

" 1. The most common mold

species worldwide is Clado. You can find a

level of clado in all buildings. "

Here again you miss the point

because you are not a mycologist nor even a biologist. Cladosporium is NOT a

species. It is a GENUS.

When you look at species level the

picture gets LOTS more complex. Almost nobody is looking or noting the species

level.

" What is the most common bug in homes? Does

the bug represent the

majority of bugs in a home? What about building

infestations. They

spread much further than mold spores. Bugs simply are

not evenly

distributed world wide. Clado, alternaria and pen

are. "

I don't know where you get your

information here. Bugs spreading much further in a home than fungi?

That is a big no. Where you have

bugs you have fungi. Both from the air, and the bugs bringing them themselves

for a variety of reasons.

Don't forget, the fungi are

predatory on the bugs themselves along with LOTS more intricate interactions.

So, this statement is just

made up.

" This is not to say, that total number of

species of bugs exceeds that

of the total number of species of mold.

But, I am not talking about species that have low

probabilities. Sure

you can find one spore of this or that. But that

is not significant,

in my opinion. "

One spore being not significant.

That may be true, but have you ever seen only one spore in a home? I think not.

" What is of interest is what can one expect

to find " normally " in any

home that is climate controlled. Since mold spores

are spread worldwide

by the atmosphere, there is a more common genera

distribution. "

Fungal spores are spread by the

atmosphere and this is common around the world. Fungal spores don't have a

worldwide distribution because

they are

spread by the wind. There are some long rangers, but they are far from going

worldwide. Now this is ecology.

" As for bacteria, SA is very common, but MRSA

is also speading. The

current LA prison outbreak is a very good example.

What bacteria is

the most predominant? We can't easily speciate

bacteria without

extensive costs and time - and the results are

highly variable. And

exactly what do they mean? "

Bacteria is a very interesting

part of the picture. However, we don't " speciate " . That is an

evolutionary process. Everyone should stop using this term.

It is incorrect, just as

" Pollens " is incorrect. Please say something like, " we need to

identify the species of bacteria.... " Just a fine point, but

important.

Also, you are dead right with the

bacteria problem. They cause a lot of problems for us. However, the bacteria

are also a large problem that we have very little

to say about. Did you know that we

have identified less than 1/2 of all the bacteria species in the human gut? And

that is right at home. This fact has lots of

implications for asthma, allergy,

and general health.

" This gets back to mold, my experience and

the almost 1,000 papers I

have read on this subject - from the last 150

years, shows typical mold

genera to be much less variable than bugs or

bacteria. "

Bob, I didn't know you were 150 years old:-) (just kidding)! Did you

think that 1,000 papers was a lot? What percentage of those are from mycology

journals? I'll bet not many related to ecology. Again, the fungi are

less variable than the other things because of the way and the length of time

we have looked.

When you filter what you look for, you will always get a smaller subset

of the whole. It is true, however, that the insects are the most diverse form

of life that we

know of.

I am not just trying to be a stone around everyone's neck, but I feel

that it is important to not overstate what we know. We still need to be

discovering in this nascent science

and excluding things on little evidence is not good. We know almost

nothing about building fungi and mold. The list of fungi and mold that I have

seen in buildings

is very long. Every time I look for something new, I find something

new. Lots of unknown species also. In fact, there many more things that I don't

know about

this subject than I know.

I sometimes feel like what Mark Twain said about the science (regarding

evolution of man), " If we continue to study it, we will soon know nothing

about it " .

He also said something like, " ...science, with such little

evidence can give us such wholesale conclusions " !

Twain also stated, " It's a terrible death to be talked to

death "

I applaud the efforts in trying to understand this issue(s). I am NOT

trying to be contentious, really.

Steve,

You bring up a good question as to whether it is

normal to have some

mold growth in a home?

The answer to this question, in most respects, is

dependent upon what

are the climatic norms for the location of the

home and what is the

home made of?

For example, in warm southern climates and the

tropics, you will find

relative humidity levels that are above 80% RH for

extended periods of

time. We are not talking hours here, we are

talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these

climatic conditions,

they will grow mold. The growth may be very slow

and in many cases

may not be visible for a few years, but it will be

there.

The spanish knew this problem and hence built

their buildings out of

stone with plaster (lime) finishes. (also note the

high pH that would

minimize mold growth, but only until it got

dirty.)

As you move to northerly climates, the time that

this level of humidity

is present decreases, but it does not go away

until you get to either

deserts or extreme arctic condition. (Summers are

very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold

growth, will occur in a

building.

Sure we can try to air condition, and dry out the

interior portions, to

minimize elevated RH, but we do not condition

every surface of the

exterior walls. Hence, some growth will eventually

occur in the

exterior walls. Just look at old buildings. Even

100 year old stone

exteriors, will have some mold on the old 2 x 4

wall studs.

A more recent area of the home where extend

elevated moisture levels

are now found are showers. Years ago, when

buildings leaked more, you

did not build up as much RH in bathrooms. But

today, with much less

air infiltration, and people who don't use their

bath exhaust fans,

you get mold in showers. The number of mold

'killing' bathroom

chemicals has significantly increased in the last

10 years.

This is another normal area where mold and other

microbes can always be

found growing in homes. This area is the drain

pipes right above the

P traps and inside of garbage disposals and in the

overflow space in

sinks. (Yes, I have smelled a few sink over flow

holes in my days-that

have turned out to be the problem.) Sometimes you

can actually smell

this mold and bacteria growth in poor ventilated

bathrooms.

Lastly, basements have a very high potential for

elevated RH. There

has been considerable discussion about crawl

spaces (on the list)

recently and what to do with them. Basements are tall

crawl spaces

with concrete floors. The water vapor below the

concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into

the basement concrete

floor and present elevated moisture levels - below

tile or any other

moisture barrier on the floor. (except in

deserts-most of the time).

Put carpeting on these concrete floors and you

grow mold, bacteria etc.

(putting in radon type sub slab ventilation can

really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say,

yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment

that consumes tons

of energy to reduce moisture in all building

materials, all the time,

you will have some mold growth in a building-because

that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

EnviroBob,

You asked,

" they likewise must have realized growth related to negative health

impacts upon the occupant. "

Haldane, et all, documented adverse health effects statistically,

around 1872.

As for the Leviticus reference- to remove mold-

well- they also warned about Trichinosis with pork- by banning it.

Bob

[Guest guest]

EnviroBob,

You asked,

" they likewise must have realized growth related to negative health

impacts upon the occupant. "

Haldane, et all, documented adverse health effects statistically,

around 1872.

As for the Leviticus reference- to remove mold-

well- they also warned about Trichinosis with pork- by banning it.

Bob

[Guest guest]

Can we agree that we need to select a better description?

YES!

Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly designed, well maintained buildings.

I don't use the term "normal fungal ecology", or the term "Condition 1", except to point out that they are concepts presently without a FUNCTIONAL, working definition. The terms are useless for practical application in the field and should either be defined so that the definition readily permits the recognition of the condition in the field, or they should be done away with altogether.

Steve Temes

Brad:

Wholeheartedly agree!

Tis why I use the term: reasonably anticipated trappings. I allows me flexibility to estimate a baseline which I believe is consistent with the hygiene of the site. If I walk into a relatively clean site, then I anticipate low trappings. If the site is dirty, then I can anticipate dirty trappings. I feel that any arbitrary fixed threshold is artificial and more often than not, unreasonable for a whole host of situations. I do not use the term: normal.

Bob, Steve and All,

Can we agree that we need to select a better description?

Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly designed, well maintained buildings.

Mold may grow in dirty showers, but a lot of effort goes into stopping it and cleaning it out.

Yeast and slim molds in waste water pipes is not a big deal in a properly designed system.

If the garbage disposal is stinking with microbial growth, don't normal, educated occupants clean it with one of the dozen products on the market designed to kill unwanted biological growth in the garbage disposal?

Bob B, where do you stop?

Lets try to start with "On a site specific basis, in a properly designed, well maintained building, without a history of unremediated moisture problems; there is an expected level of fungal components in the air and on surfaces in settled dust. The fungal components can originate from a number of sources and change rapidly based upon source loading factors and building design and operation. For example, fungal components may originate from the outdoor air, occupant activities, house plants, and other deminimus wet areas in the building such as toilets and drain pipes. Geographic regions with extended periods of high relative humidity will typically have the potential for higher indoor fungal levels, however, frequency of cleaning and the level of mechanical air filtration and dehumidification will influence the actual level of fungal components typically found in the indoor environment on a site specific basis".

Lets all try to make a better definition, and I don't care how long it is, so long as it makes sense and is correct.

Bradley Harr

Sr. Environmental Scientist

Re: Normal Fungal Ecology

I guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological component

to building mold, but I stop there. Discovering mold growth in a home is normal, not ecology.

[Guest guest]

Just because you do not use air conditioning does not mean that you can have improved indoor RH control; go for an EnergyStar rated dehumidifier.

If I could ever get the ear of the right people I could show them to reduce energy use in these devices by about 50%, but no one that I have contacted is interested.

Modern air conditioners do not remove as much moisture as they did historically, due to the energy rating standard changes, but they do help some. If you run an air conditioner, therefore, you should also run a good dehumidifier and set the temperature higher; for more comfort, not less.

Jim H. White System Science Consulting

Re: Normal Fungal Ecology

Steve:I too believe that there is a normal biological ecology in all structures; some more, some less. Take for example the hot humid Southeast, e.g., east Texas, Mississippi, and Georgia. Mold growth on surfaces in not uncommon and it can be very normal. Mitigating mold growth in bathrooms is a significant housekeeping chore in the southeast. Some folks are better at it than others, and some are fastidious about cleanliness. And what does it take to keep the mold a bay?.....lots and lots of caustic and potentially harmful chemicals! So which is worse and which is doing more harm? (A rhetorical question that does not warrant an answer.) Why not accept that some ecology is going to happen? Also, take for example the Pacific Northwest where leather goods (jackets, handbags, belts, etc.), will mold in your closet (nice white and green colonies too!); because closets typically have inadequate air flow and the air is cool and humid. Not much AC use in these climates. Normal is where normal is.I for one, believe that some biology indoors is normal, it should be accepted as normal, and it should be a housekeeping issue – not representative of “contamination” as mentioned in IICRC’s S520. Drawing the line as to what is acceptable in your house, versus my house, versus Doe’s house, is the “crux of the biscuit” (to quote Zappa). Modern society has been lead to believe the Lysol commercials that the home should be free of germs, bacteria and mold, and be made to smell “Lysol fresh.” Choke!...Gasp!.....Yeah right!, and all the chemicals that go along with Lysol too. Does the IICRC do us a favor defining: normal fungal ecology,.....not sure, but it is a start. I sort of like Bob’s idea (it was Bob wasn’t it?), i.e., if it isn’t Condition 2 or Condition 3, then maybe it is: normal. Not perfect, but the idea has merit.For what it is worth....On 8/27/07 2:34 PM, "AirwaysEnvcs" <AirwaysEnvcs> wrote:

Bob s wrote: "So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology."Bob,I understand very well what you are saying and have no disagreement with the fact that mold can and does grow indoors and on building materials when there is moisture present. I also don't disagree that it is "normal" in a statistical sense for any given house to have indoor mold growth occurring somewhere.The problem I have is with the IICRC definition (or lack thereof) of their term "normal fungal ecology" in the context of an environmental assessment and how decisions are to be made by an IEP based on their term "Conditon 1". It essentially means that, for those "normal" indoor growth issues you raised, no remediation would be indicated because it is normal. Or worse, the definition of Condition 1 can be used to say that the levels of spores are "normal", therefore further remediation is not necessary.I am not arguing that it isn't normal for some mold growth to occur in a given structure at some point in time. Or that potted plants, or dogs going in and out, don't contribute to mold spores being present indoors normally. I'm saying that indoor mold growth does not meet the strict definition of fungal ecology (organisms competing against one another in their ecological niches as Shane discussed) unless the house is composting. And I am saying that it is not REALLY "normal", since visible mold growth in indoor environments is unacceptable and is an indication of a moisture problem.So, even if I agree in principle that normal fungal ecology exists in an indoor environment to the extent that it is normal for it to get wet (where that might be normal), I still don't agree that it should be considered Condition 1 for decision-making purposes. If you can identify how and why mold growth occurs indoors for the reasons you listed, and many others, why isn't this indoor growth considered Condition 3 or Condition 2? And if it is Condition 3 or Condition 2, it isn't normal fungal ecology by IICRC definition.It is the IICRC definition of "normal fungal ecology" and Condition 1 that is confusing, not that mold grows in buildings for the reasons you have discussed. Normal implies acceptable. Indoor fungal growth should only be considered normal if it is acceptable. It is hard to make the case that indoor growth is acceptable, no matter how normal it might be.Steve TemesIn a message dated 8/27/2007 10:52:54 AM Eastern Daylight Time, BobBsafety-epa writes:

Steve,You bring up a good question as to whether it is normal to have some mold growth in a home?The answer to this question, in most respects, is dependent upon what are the climatic norms for the location of the home and what is the home made of?For example, in warm southern climates and the tropics, you will find relative humidity levels that are above 80% RH for extended periods of time. We are not talking hours here, we are talking about days, weeks, or many months.If you present wood, paper, drywall, etc to these climatic conditions, they will grow mold. The growth may be very slow and in many cases may not be visible for a few years, but it will be there.The spanish knew this problem and hence built their buildings out of stone with plaster (lime) finishes. (also note the high pH that would minimize mold growth, but only until it got dirty.)As you move to northerly climates, the time that this level of humidity is present decreases, but it does not go away until you get to either deserts or extreme arctic condition. (Summers are very humid up in Canada and so is the wet soil.)During these climate conditions, normal mold growth, will occur in a building.Sure we can try to air condition, and dry out the interior portions, to minimize elevated RH, but we do not condition every surface of the exterior walls. Hence, some growth will eventually occur in the exterior walls. Just look at old buildings. Even 100 year old stone exteriors, will have some mold on the old 2 x 4 wall studs.A more recent area of the home where extend elevated moisture levels are now found are showers. Years ago, when buildings leaked more, you did not build up as much RH in bathrooms. But today, with much less air infiltration, and people who don't use their bath exhaust fans, you get mold in showers. The number of mold 'killing' bathroom chemicals has significantly increased in the last 10 years.This is another normal area where mold and other microbes can always be found growing in homes. This area is the drain pipes right above the P traps and inside of garbage disposals and in the overflow space in sinks. (Yes, I have smelled a few sink over flow holes in my days-that have turned out to be the problem.) Sometimes you can actually smell this mold and bacteria growth in poor ventilated bathrooms.Lastly, basements have a very high potential for elevated RH. There has been considerable discussion about crawl spaces (on the list) recently and what to do with them. Basements are tall crawl spaces with concrete floors. The water vapor below the concrete (w/o a vapor retarder or a disintegrated VB) will diffuse into the basement concrete floor and present elevated moisture levels - below tile or any other moisture barrier on the floor. (except in deserts-most of the time). Put carpeting on these concrete floors and you grow mold, bacteria etc. (putting in radon type sub slab ventilation can really minimize this problem.- but at an energy cost.)So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology.Bob

[Guest guest]

EnviroBob, et al.: "What is normal"? The only definition of "normal" I have discovered to be effective is the setting on my washing machine. Anyone else want to give it a try? Pete EnviroBob wrote: Bradley, I concur with what you have said below. I also agree that there will be a distribution of fungal components due to mice, cats, dogs, shoes, and open doors and windows. Again you will notice I did not say normal because what distributional impacts will each of these have and at what ratio? Additionally, these distributions are not actual growth only distributions of spores and/or particulate(s). Without playing on words, mold does not grow in the air. Furthermore knowing fungi consumes its host, who would knowingly build a building that would be decomposed by mold? What would the expected life of the building be? We build them to avoid mold growth. So what is

normal growth? None, per intended design!! Keep in mind here; so far the emphasis has been on growth not particulate. And with a good cleaning, the particulate should be removed and the expected results should be below background. Keep in mind; unless it is snow covered the infiltrated air will migrate through the insulated (filtered) wall thus the inside should be below the outside again unless the door and windows are opened. So what is normal? EnviroBob From: iequality [mailto:iequality ] On Behalf Of Brad HarrSent: Tuesday, August 28, 2007 2:18 PMTo:

iequality Subject: RE: Normal Fungal Ecology Bob, Steve and All, Can we agree that we need to select a better description? Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly designed, well maintained buildings. Mold may grow in dirty showers, but a lot of effort goes into stopping it and cleaning it out. Yeast and slim molds in waste water pipes is not a

big deal in a properly designed system. If the garbage disposal is stinking with microbial growth, don't normal, educated occupants clean it with one of the dozen products on the market designed to kill unwanted biological growth in the garbage disposal? Bob B, where do you stop? Lets try to start with "On a site specific basis, in a properly designed, well

maintained building, without a history of unremediated moisture problems; there is an expected level of fungal components in the air and on surfaces in settled dust. The fungal components can originate from a number of sources and change rapidly based upon source loading factors and building design and operation. For example, fungal components may originate from the outdoor air, occupant activities, house plants, and other deminimus wet areas in the building such as toilets and drain pipes. Geographic regions with extended periods of high relative humidity will typically have the potential for higher indoor fungal levels, however, frequency of cleaning and the level of mechanical air filtration and dehumidification will influence the actual level of fungal components typically found in the indoor environment on a site specific basis". Lets all try to make a better definition, and I don't care how long it is, so long as it makes sense and is correct. Bradley HarrSr. Environmental Scientist -----Original Message-----From: iequality [mailto:iequality ]On Behalf Of

ShaneSent: Tuesday, August 28, 2007 5:53 AMTo: iequality Subject: Re: Normal Fungal Ecology I guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological component to building mold, but I stop there. Discovering mold growth in a home is normal, not ecology. "1. The most common mold species worldwide is Clado. You can find a level of clado in all buildings." Here again you

miss the point because you are not a mycologist nor even a biologist. Cladosporium is NOT a species. It is a GENUS. When you look at species level the picture gets LOTS more complex. Almost nobody is looking or noting the species level. "What is the most common bug in homes? Does the bug represent the majority of bugs in a home? What about building infestations. They spread much further than mold spores. Bugs simply are not evenly distributed world wide. Clado, alternaria and pen

are." I don't know where you get your information here. Bugs spreading much further in a home than fungi? That is a big no. Where you have bugs you have fungi. Both from the air, and the bugs bringing them themselves for a variety of reasons. Don't forget, the fungi are predatory on the bugs themselves along with LOTS more

intricate interactions. So, this statement is just made up."This is not to say, that total number of species of bugs exceeds that of the total number of species of mold.But, I am not talking about species that have low probabilities. Sure you can find one spore of this or that. But that is not significant, in my opinion." One spore being not significant. That may be true, but have you ever seen only one spore in a home? I think not."What is of interest is what can one expect to find "normally" in any home that is climate controlled. Since mold spores are spread worldwide by the atmosphere, there is a more common genera distribution." Fungal spores are

spread by the atmosphere and this is common around the world. Fungal spores don't have a worldwide distribution because they are spread by the wind. There are some long rangers, but they are far from going worldwide. Now this is ecology."As for bacteria, SA is very common, but MRSA is also speading. The current LA prison outbreak is a very good example. What bacteria is the most predominant? We can't easily speciate bacteria without extensive costs and time - and the results are highly variable. And exactly

what do they mean?" Bacteria is a very interesting part of the picture. However, we don't "speciate". That is an evolutionary process. Everyone should stop using this term. It is incorrect, just as "Pollens" is incorrect. Please say something like, "we need to identify the species of bacteria...." Just a fine point, but important. Also, you are dead right with the bacteria problem. They cause a lot of problems for us. However, the bacteria are also a

large problem that we have very little to say about. Did you know that we have identified less than 1/2 of all the bacteria species in the human gut? And that is right at home. This fact has lots of implications for asthma, allergy, and general health. "This gets back to mold, my experience and the almost 1,000 papers I have read on this subject - from the last 150 years, shows typical mold genera to be much less variable than bugs or bacteria." Bob, I didn't know you were 150 years old:-) (just kidding)! Did you think that 1,000 papers was a lot? What percentage of those are from mycology journals? I'll bet not many related to ecology. Again, the fungi are less variable than the other things because of the way and the length of time we have looked. When you filter what you look for, you will always get a smaller subset of the

whole. It is true, however, that the insects are the most diverse form of life that we know of. I am not just trying to be a stone around everyone's neck, but I feel that it is important to not overstate what we know. We still need to be discovering in this nascent science and excluding things on little evidence is not good. We know almost nothing about building fungi and mold. The list of fungi and mold that I have seen in buildings is very long. Every time I look for something new, I find something new. Lots of unknown species also. In fact, there many more things that I don't know about this subject than I know. I sometimes feel like what Mark Twain said about the science (regarding evolution of man), "If we continue to study it, we will soon know nothing about it". He also said something like, "...science, with such little evidence can give us such wholesale conclusions"! Twain also stated, "It's a terrible death to be talked to death" I applaud the efforts in trying to understand this issue(s). I am NOT trying to be contentious, really. Steve,You bring up a good question as to whether it is normal to have some mold growth in a home?The answer to this question, in most respects, is dependent upon what are the climatic norms for the location of the home and what is the home made of?For example, in warm southern climates and the tropics, you will find relative humidity levels that are above 80% RH for extended periods of time. We are not talking hours here, we are talking about days, weeks, or many

months.If you present wood, paper, drywall, etc to these climatic conditions, they will grow mold. The growth may be very slow and in many cases may not be visible for a few years, but it will be there.The spanish knew this problem and hence built their buildings out of stone with plaster (lime) finishes. (also note the high pH that would minimize mold growth, but only until it got dirty.)As you move to northerly climates, the time that this level of humidity is present decreases, but it does not go away until you get to either deserts or extreme arctic condition. (Summers are very humid up in

Canada and so is the wet soil.)During these climate conditions, normal mold growth, will occur in a building.Sure we can try to air condition, and dry out the interior portions, to minimize elevated RH, but we do not condition every surface of the exterior walls. Hence, some growth will eventually occur in the exterior walls. Just look at old buildings. Even 100 year old stone exteriors, will have some mold on the old 2 x 4 wall studs.A more recent area of the home where extend elevated moisture levels are now

found are showers. Years ago, when buildings leaked more, you did not build up as much RH in bathrooms. But today, with much less air infiltration, and people who don't use their bath exhaust fans, you get mold in showers. The number of mold 'killing' bathroom chemicals has significantly increased in the last 10 years.This is another normal area where mold and other microbes can always be found growing in homes. This area is the drain pipes right above the P traps and inside of garbage disposals and in the overflow space in sinks. (Yes, I have smelled a few sink over flow holes in my days-that have turned out to be

the problem.) Sometimes you can actually smell this mold and bacteria growth in poor ventilated bathrooms.Lastly, basements have a very high potential for elevated RH. There has been considerable discussion about crawl spaces (on the list) recently and what to do with them. Basements are tall crawl spaces with concrete floors. The water vapor below the concrete (w/o a vapor retarder or a disintegrated VB) will diffuse into the basement concrete floor and present elevated moisture levels - below tile or any other moisture barrier on the floor. (except in deserts-most of the time). Put carpeting on these concrete

floors and you grow mold, bacteria etc. (putting in radon type sub slab ventilation can really minimize this problem.- but at an energy cost.)So is mold growth normal in a home? I would say, yes. Mold growth is a fact of the natural ecosystem.Unless one manufacturers an artificial environment that consumes tons of energy to reduce moisture in all building materials, all the time, you will have some mold growth in a building-because that this the natural normal ecology.ei normal fungal ecology.Bob

Luggage? GPS? Comic books?

Check out fitting gifts for grads at Yahoo! Search.

[Guest guest]

Brad, Steve, Agreed. (1) Normal ecology vs. acceptable (safe?) level Fungal spores (100,000 spores/in2) grew slowly in the past two years is not any better than same amount of fungal spores grew in the past two days after a water damage. Well, maybe a little bit, but not a whole lot. It's still mold and need to be removed if it can cause problem in either cases. "Normal" seems to mean "no water damage" history in a "properly designed and well-maintained building" (thanks, Brad), but it doesn't mean it's totally ok for those fungal biomass to be left behind. It need to be evaluated case by case. (2) Condition1, 2, and 3 not exclusive of each other Base on IICRC definitions, Condition 1 could possibly have higher amount of fungal biomass than Condition 2. How do you remediate to a higher level than it already has? IMHO, Condition 1 should have only low

density loose fungal biomass (spores and hyphal fragments) deposited from air. A mold growth is a mold growth. It doesn't matter how long it takes to get that. (3) Pre-loss vs. clean "Normal" seems to mean "no water damage" history in a properly designed well-maintained building, and "normal fungal ecology" seems to mean a pre-loss condition. You need to have a huge database for fungal biomass levels in many different materials in many different type of building in many different climates, etc, etc. It's going to be a very difficult task to have that. It seems more feasible to establish numbers of fungal spores and hyphal fragments can be reduced to in common cost effective ways currently used by remediators. If other remediators can have it this clean while spending reasonable amount of money, why can't you do that? Don't you want to do better than your competitors, or at least the same?

Wei Tang QLabAirwaysEnv@... wrote: Can we agree that we need to select a better description? YES!Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly designed, well maintained buildings.I don't use the term "normal fungal ecology", or the term "Condition 1", except to point out that they are concepts presently without a FUNCTIONAL, working definition. The terms are useless for practical application in the field and should either be defined so that the definition readily permits the recognition of the condition in the field, or they should be done away with altogether.Steve TemesIn a message dated 8/29/2007 11:15:54 AM Eastern Daylight Time, mgeyeratg1 writes:

Brad:Wholeheartedly agree!Tis why I use the term: reasonably anticipated trappings. I allows me flexibility to estimate a baseline which I believe is consistent with the hygiene of the site. If I walk into a relatively clean site, then I anticipate low trappings. If the site is dirty, then I can anticipate dirty trappings. I feel that any arbitrary fixed threshold is artificial and more often than not, unreasonable for a whole host of situations. I do not use the term: normal.On 8/28/07 11:18 AM, "Brad Harr" <bdharrsummitenviroinc> wrote: Bob, Steve and All,Can we agree that we need to select a better description? Let's stop using "normal fungal ecology" to describe fungal components in indoor air and dust in properly

designed, well maintained buildings.Mold may grow in dirty showers, but a lot of effort goes into stopping it and cleaning it out. Yeast and slim molds in waste water pipes is not a big deal in a properly designed system.If the garbage disposal is stinking with microbial growth, don't normal, educated occupants clean it with one of the dozen products on the market designed to kill unwanted biological growth in the garbage disposal? Bob B, where do you stop? Lets try to start with "On a site specific basis, in a properly designed, well maintained building, without a history of unremediated moisture problems; there is an expected level of fungal components in the air and on surfaces in settled dust. The fungal components can originate from a number of sources and change rapidly based upon source loading factors and building design and operation. For example, fungal components may originate from the outdoor air, occupant activities, house plants, and other deminimus wet areas in the building such as toilets and drain pipes. Geographic regions with extended periods of high relative humidity will typically have the potential for higher indoor fungal levels, however, frequency of cleaning and the level of mechanical air filtration and dehumidification will influence the actual level of fungal components typically found in the indoor environment on a site specific

basis". Lets all try to make a better definition, and I don't care how long it is, so long as it makes sense and is correct. Bradley HarrSr. Environmental Scientist -----Original

Message-----From: iequality [mailto:iequality ]On Behalf Of ShaneSent: Tuesday, August 28, 2007 5:53 AMTo: iequality Subject: Re: Normal Fungal EcologyI guess we will just have to disagree on this one guys. Perhaps we need a "settled dust" or "accumulated fungal flora" moniker for this thing. I agree that there certainly IS an ecological component to building mold, but I stop there. Discovering mold growth in a home is normal, not ecology. Wei Tang, Ph.D. Lab Director QLab5 DriveCherry Hill, NJ

08003www.QLabUSA.com

[Guest guest]

Jim,

That is true. When drying a water loss during

the high RH it feels very hot, remove the excess moisture and even though the

tempo is high it feels cooler. Now your body evaporation system is more

efficient making you feel cooler (correct?). I think the real issue for them

would be selling warmer temps as the general public is expecting to see the

temp lower and that is how they have sold units in the past.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Jim H. White

Sent: Wednesday, August 29, 2007

10:19 AM

To: iequality

Subject: Re: Normal

Fungal Ecology

Just because you do not use air conditioning does not mean

that you can have improved indoor RH control; go for an EnergyStar rated

dehumidifier.

If I could ever get the ear of the right people I could show

them to reduce energy use in these devices by about 50%, but no one that I have

contacted is interested.

Modern air conditioners do not remove as much moisture as

they did historically, due to the energy rating standard changes, but they do

help some. If you run an air conditioner, therefore, you should also run a

good dehumidifier and set the temperature higher; for more comfort, not less.

Jim H. White System Science Consulting

Re:

Normal Fungal Ecology

Steve:

I too believe that there is a normal biological ecology in all structures; some

more, some less. Take for example the hot humid Southeast, e.g., east Texas, Mississippi, and Georgia.

Mold growth on surfaces in not uncommon and it can be very normal.

Mitigating mold growth in bathrooms is a significant housekeeping chore

in the southeast. Some folks are better at it than others, and some are

fastidious about cleanliness. And what does it take to keep the mold a

bay?.....lots and lots of caustic and potentially harmful chemicals! So

which is worse and which is doing more harm? (A rhetorical question that

does not warrant an answer.) Why not accept that some ecology is going to

happen? Also, take for example the Pacific Northwest where leather goods

(jackets, handbags, belts, etc.), will mold in your closet (nice white and green

colonies too!); because closets typically have inadequate air flow and the air

is cool and humid. Not much AC use in these climates. Normal is where normal

is.

I for one, believe that some biology indoors is normal, it should be accepted

as normal, and it should be a housekeeping issue – not representative of

“contamination” as mentioned in IICRC’s S520. Drawing

the line as to what is acceptable in your house, versus my house, versus

Doe’s house, is the “crux of the biscuit” (to quote Zappa).

Modern society has been lead to believe the Lysol commercials that the

home should be free of germs, bacteria and mold, and be made to smell

“Lysol fresh.” Choke!...Gasp!.....Yeah right!, and all

the chemicals that go along with Lysol too. Does the IICRC do us a favor

defining: normal fungal ecology,.....not sure, but it is a start. I

sort of like Bob’s idea (it was Bob wasn’t it?), i.e., if it

isn’t Condition 2 or Condition 3, then maybe it is: normal. Not

perfect, but the idea has merit.

For what it is worth....

On 8/27/07 2:34 PM, " AirwaysEnvcs " <AirwaysEnvcs>

wrote:

Bob s wrote: " So is mold growth normal in a home? I would

say, yes. Mold growth is a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology. "

Bob,

I understand very well what you are saying and have no disagreement with the

fact that mold can and does grow indoors and on building materials when there

is moisture present. I also don't disagree that it is " normal "

in a statistical sense for any given house to have indoor mold growth occurring

somewhere.

The problem I have is with the IICRC definition (or lack thereof) of their term

" normal fungal ecology " in the context of an environmental assessment

and how decisions are to be made by an IEP based on their term " Conditon

1 " . It essentially means that, for those " normal " indoor

growth issues you raised, no remediation would be indicated because it is

normal. Or worse, the definition of Condition 1 can be used to say that

the levels of spores are " normal " , therefore further remediation is

not necessary.

I am not arguing that it isn't normal for some mold growth to occur in a given

structure at some point in time. Or that potted plants, or dogs going in

and out, don't contribute to mold spores being present indoors normally.

I'm saying that indoor mold growth does not meet the strict definition of

fungal ecology (organisms competing against one another in their ecological

niches as Shane discussed) unless the house is composting. And I am

saying that it is not REALLY " normal " , since visible mold growth in

indoor environments is unacceptable and is an indication of a moisture problem.

So, even if I agree in principle that normal fungal ecology exists in an indoor

environment to the extent that it is normal for it to get wet (where that might

be normal), I still don't agree that it should be considered Condition 1 for

decision-making purposes. If you can identify how and why mold growth

occurs indoors for the reasons you listed, and many others, why isn't this indoor

growth considered Condition 3 or Condition 2? And if it is Condition 3 or

Condition 2, it isn't normal fungal ecology by IICRC definition.

It is the IICRC definition of " normal fungal ecology " and Condition 1

that is confusing, not that mold grows in buildings for the reasons you have

discussed. Normal

implies acceptable. Indoor fungal growth should only be considered normal

if it is acceptable. It is hard to make the case that indoor growth is

acceptable, no matter how normal it might be.

Steve Temes

In a message dated 8/27/2007 10:52:54 AM Eastern Daylight Time, BobBsafety-epa

writes:

Steve,

You bring up a good question as to whether it is normal to have some

mold growth in a home?

The answer to this question, in most respects, is dependent upon what

are the climatic norms for the location of the home and what is the

home made of?

For example, in warm southern climates and the tropics, you will find

relative humidity levels that are above 80% RH for extended periods of

time. We are not talking hours here, we are talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these climatic conditions,

they will grow mold. The growth may be very slow and in many cases

may not be visible for a few years, but it will be there.

The spanish knew this problem and hence built their buildings out of

stone with plaster (lime) finishes. (also note the high pH that would

minimize mold growth, but only until it got dirty.)

As you move to northerly climates, the time that this level of humidity

is present decreases, but it does not go away until you get to either

deserts or extreme arctic condition. (Summers are very humid up in

Canada

and so is the wet soil.)

During these climate conditions, normal mold growth, will occur in a

building.

Sure we can try to air condition, and dry out the interior portions, to

minimize elevated RH, but we do not condition every surface of the

exterior walls. Hence, some growth will eventually occur in the

exterior walls. Just look at old buildings. Even 100 year old stone

exteriors, will have some mold on the old 2 x 4 wall studs.

A more recent area of the home where extend elevated moisture levels

are now found are showers. Years ago, when buildings leaked more, you

did not build up as much RH in bathrooms. But today, with much less

air infiltration, and people who don't use their bath exhaust fans,

you get mold in showers. The number of mold 'killing' bathroom

chemicals has significantly increased in the last 10 years.

This is another normal area where mold and other microbes can always be

found growing in homes. This area is the drain pipes right above the

P traps and inside of garbage disposals and in the overflow space in

sinks. (Yes, I have smelled a few sink over flow holes in my days-that

have turned out to be the problem.) Sometimes you can actually smell

this mold and bacteria growth in poor ventilated bathrooms.

Lastly, basements have a very high potential for elevated RH. There

has been considerable discussion about crawl spaces (on the list)

recently and what to do with them. Basements are tall crawl spaces

with concrete floors. The water vapor below the concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into the basement concrete

floor and present elevated moisture levels - below tile or any other

moisture barrier on the floor. (except in deserts-most of the time).

Put carpeting on these concrete floors and you grow mold, bacteria etc.

(putting in radon type sub slab ventilation can really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say, yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment that consumes tons

of energy to reduce moisture in all building materials, all the time,

you will have some mold growth in a building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

[Guest guest]

Bob B,

I totally agree and that is why I use

below (much) background especially when you consider the building acts like a

filtration system (unless doors and windows are open). And due to your earlier

statements (Below) I do not expect the growth to be occurring inside. Otherwise

I will have to tear it down and put it in the dump outside the camp (city dump).

Now so far I have determined that God knows more than me so I will use theses

standards until He writes another Bible and changes the mold statements.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Bob s

Sent: Tuesday, August 28, 2007

9:34 PM

To: iequality

Subject: Re: Normal

Fungal Ecology

EnviroBob,

You asked,

" they likewise must have realized growth related to negative health

impacts upon the occupant. "

Haldane, et all, documented adverse health effects statistically, around 1872.

As for the Leviticus reference- to remove mold-

well- they also warned about Trichinosis with pork- by banning it.

Bob

[Guest guest]

Pete,

I concur. That is normal whatever that is.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Pete Carkhuff

Sent: Wednesday, August 29, 2007

12:03 PM

To: iequality

Subject: RE: Normal

Fungal Ecology

EnviroBob, et al.:

" What is normal " ?

The only definition of " normal " I have discovered to

be effective is the setting on my washing machine.

Anyone else want to give it a try?

Pete

EnviroBob

<BobEnvironmentalAirTechs> wrote:

Bradley,

I concur with what you have said

below. I also agree that there will be a distribution of fungal components due

to mice, cats, dogs, shoes, and open doors and windows. Again you will notice I

did not say normal because what distributional impacts will each of these have

and at what ratio? Additionally, these distributions are not actual growth only

distributions of spores and/or particulate(s). Without playing on words,

mold does not grow in the air. Furthermore knowing fungi consumes its host, who

would knowingly build a building that would be decomposed by mold? What would

the expected life of the building be? We build them to avoid mold growth. So

what is normal growth? None, per intended design!!

Keep in mind here; so far the

emphasis has been on growth not particulate. And with a good cleaning, the

particulate should be removed and the expected results should be below

background. Keep in mind; unless it is snow covered the infiltrated air will

migrate through the insulated (filtered) wall thus the inside should be below

the outside again unless the door and windows are opened. So what is normal?

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Brad Harr

Sent: Tuesday, August 28, 2007

2:18 PM

To: iequality

Subject: RE: Normal

Fungal Ecology

Bob, Steve and All,

Can we agree that we need to select

a better

description?

Let's stop using " normal

fungal ecology " to describe fungal components in indoor air and dust in

properly designed, well maintained buildings.

Mold may grow in dirty showers, but

a lot of effort goes into stopping it and cleaning it out.

Yeast and slim molds in waste water pipes

is not a big deal in a properly designed system.

If the garbage disposal is stinking with

microbial growth, don't normal, educated occupants clean it with one of the

dozen products on the market designed to kill unwanted biological growth

in the garbage disposal?

Bob B, where do you stop?

Lets try to start with " On a

site specific basis, in a properly designed, well maintained building, without

a history of unremediated moisture problems; there is an expected level of

fungal components in the air and on surfaces in settled dust. The fungal

components can originate from a number of sources and change rapidly based

upon source loading factors and building design and

operation. For example, fungal components may originate from

the outdoor air, occupant activities, house plants, and other deminimus wet

areas in the building such as toilets and drain pipes. Geographic regions

with extended periods of high relative humidity will typically have the

potential for higher indoor fungal levels, however, frequency of cleaning and

the level of mechanical air filtration and dehumidification will influence the

actual level of fungal components typically found in the indoor

environment on a site specific basis " .

Lets all try to make a better definition,

and I don't care how long it is, so long as it makes sense and is

correct.

Bradley Harr

Sr. Environmental Scientist

Re: Normal

Fungal Ecology

I guess we will just have to disagree on this one guys. Perhaps we need

a " settled dust " or " accumulated fungal flora " moniker for

this thing. I agree that there certainly IS an ecological component

to building mold, but I stop there. Discovering mold growth in a home

is normal, not ecology.

" 1.

The most common mold species worldwide is Clado. You can find a

level of clado in all buildings. "

Here again you

miss the point because you are not a mycologist nor even a biologist.

Cladosporium is NOT a species. It is a GENUS.

When you look at species level the

picture gets LOTS more complex. Almost nobody is looking or noting the species

level.

" What is the most common bug in homes? Does

the bug represent the

majority of bugs in a home? What about building

infestations. They

spread much further than mold spores. Bugs simply

are not evenly

distributed world wide. Clado, alternaria and pen

are. "

I don't know

where you get your information here. Bugs spreading much further in a home than

fungi?

That is a big no. Where you have

bugs you have fungi. Both from the air, and the bugs bringing them themselves

for a variety of reasons.

Don't forget, the fungi are

predatory on the bugs themselves along with LOTS more intricate interactions.

So, this statement is just

made up.

" This is not to say, that total number of

species of bugs exceeds that

of the total number of species of mold.

But, I am not talking about species that have low

probabilities. Sure

you can find one spore of this or that. But that

is not significant,

in my opinion. "

One spore being

not significant. That may be true, but have you ever seen only one spore in a

home? I think not.

" What is of interest is what can one expect

to find " normally " in any

home that is climate controlled. Since mold spores

are spread worldwide

by the atmosphere, there is a more common genera

distribution. "

Fungal spores

are spread by the atmosphere and this is common around the world. Fungal spores

don't have a worldwide distribution because

they are spread by the wind. There

are some long rangers, but they are far from going worldwide. Now this is

ecology.

" As for bacteria, SA is very common, but MRSA

is also speading. The

current LA prison outbreak is a very good example.

What bacteria is

the most predominant? We can't easily speciate

bacteria without

extensive costs and time - and the results are

highly variable. And

exactly what do they mean? "

Bacteria is a very interesting

part of the picture. However, we don't " speciate " . That is an

evolutionary process. Everyone should stop using this term.

It is incorrect, just as

" Pollens " is incorrect. Please say something like, " we need to

identify the species of bacteria.... " Just a fine point, but

important.

Also, you are dead right with the

bacteria problem. They cause a lot of problems for us. However, the bacteria

are also a large problem that we have very little

to say about. Did you know that we

have identified less than 1/2 of all the bacteria species in the human gut? And

that is right at home. This fact has lots of

implications for asthma, allergy,

and general health.

" This gets back to mold, my experience and

the almost 1,000 papers I

have read on this subject - from the last 150

years, shows typical mold

genera to be much less variable than bugs or

bacteria. "

Bob, I didn't know you were 150 years old:-) (just kidding)! Did

you think that 1,000 papers was a lot? What percentage of those are from

mycology

journals? I'll bet not many related to ecology. Again, the fungi are

less variable than the other things because of the way and the length of time

we have looked.

When you filter what you look for, you will always get a smaller subset

of the whole. It is true, however, that the insects are the most diverse form

of life that we

know of.

I am not just trying to be a stone around everyone's neck, but I

feel that it is important to not overstate what we know. We still need to be

discovering in this nascent science

and excluding things on little evidence is not good. We know almost

nothing about building fungi and mold. The list of fungi and mold that I have

seen in buildings

is very long. Every time I look for something new, I find something

new. Lots of unknown species also. In fact, there many more things that I don't

know about

this subject than I know.

I sometimes feel like what Mark Twain said about the science

(regarding evolution of man), " If we continue to study it, we will soon

know nothing about it " .

He also said something like, " ...science, with such little

evidence can give us such wholesale conclusions " !

Twain also stated, " It's a terrible death to be talked to

death "

I applaud the efforts in trying to understand this issue(s). I

am NOT trying to be contentious, really.

Steve,

You bring up a good question as to whether it is

normal to have some

mold growth in a home?

The answer to this question, in most respects, is

dependent upon what

are the climatic norms for the location of the

home and what is the

home made of?

For example, in warm southern climates and the

tropics, you will find

relative humidity levels that are above 80% RH for

extended periods of

time. We are not talking hours here, we are

talking about days,

weeks, or many months.

If you present wood, paper, drywall, etc to these

climatic conditions,

they will grow mold. The growth may be very slow

and in many cases

may not be visible for a few years, but it will be

there.

The spanish knew this problem and hence built

their buildings out of

stone with plaster (lime) finishes. (also note the

high pH that would

minimize mold growth, but only until it got

dirty.)

As you move to northerly climates, the time that

this level of humidity

is present decreases, but it does not go away

until you get to either

deserts or extreme arctic condition. (Summers are

very humid up in

Canada and so is the wet soil.)

During these climate conditions, normal mold

growth, will occur in a

building.

Sure we can try to air condition, and dry out the

interior portions, to

minimize elevated RH, but we do not condition

every surface of the

exterior walls. Hence, some growth will eventually

occur in the

exterior walls. Just look at old buildings. Even

100 year old stone

exteriors, will have some mold on the old 2 x 4

wall studs.

A more recent area of the home where extend

elevated moisture levels

are now found are showers. Years ago, when

buildings leaked more, you

did not build up as much RH in bathrooms. But

today, with much less

air infiltration, and people who don't use their

bath exhaust fans,

you get mold in showers. The number of mold

'killing' bathroom

chemicals has significantly increased in the last

10 years.

This is another normal area where mold and other

microbes can always be

found growing in homes. This area is the drain

pipes right above the

P traps and inside of garbage disposals and in the

overflow space in

sinks. (Yes, I have smelled a few sink over flow

holes in my days-that

have turned out to be the problem.) Sometimes you

can actually smell

this mold and bacteria growth in poor ventilated

bathrooms.

Lastly, basements have a very high potential for

elevated RH. There

has been considerable discussion about crawl

spaces (on the list)

recently and what to do with them. Basements are

tall crawl spaces

with concrete floors. The water vapor below the

concrete (w/o a vapor

retarder or a disintegrated VB) will diffuse into

the basement concrete

floor and present elevated moisture levels - below

tile or any other

moisture barrier on the floor. (except in

deserts-most of the time).

Put carpeting on these concrete floors and you

grow mold, bacteria etc.

(putting in radon type sub slab ventilation can

really minimize this

problem.- but at an energy cost.)

So is mold growth normal in a home? I would say,

yes. Mold growth is

a fact of the natural ecosystem.

Unless one manufacturers an artificial environment

that consumes tons

of energy to reduce moisture in all building

materials, all the time,

you will have some mold growth in a

building-because that this the

natural normal ecology.

ei normal fungal ecology.

Bob

Luggage? GPS? Comic books?

Check out fitting gifts

for grads at Yahoo! Search.

[Guest guest]

,

You want to attribute "contamination" as per IICRC's S520 to be due to "housekeeping issues" and accepted as "normal" amounts of mold found in homes? I am referencing your statement below in your post to mean inclusion of molds with the types of spores more specifically linked to causing health problems.

So I ask you, what part of this do you consider to be in the best interest of the health and safety of the occupant? The part that would establish acceptable levels of mycotoxin producing molds to be in homes? Or the part where you imply that these "normal" levels of spores found in homes are due to poor housekeeping skills?

As to what is an acceptable amount of "biology" within a home, please do not attempt to casually throw molds into this unknown equation and mix of yours as to what you construe to be "normal."

Bobbins, RN, L.Ac, QME

I for one, believe that some biology indoors is normal, it should be accepted as normal, and it should be a housekeeping issue – not representative of “contamination†as mentioned in IICRC’s S520. Drawing the line as to what is acceptable in your house, versus my house, versus Doe’s house, is the “crux of the biscuit†(to quote Zappa). Modern society has been lead to believe the Lysol commercials that the home should be free of germs, bacteria and mold, and be made to smell “Lysol fresh.†Choke!...Gasp!.....Yeah right!, and all the chemicals that go along with Lysol too. Does the IICRC do us a favor defining: normal fungal ecology,.....not sure, but it is a start. I sort of like Bob’s idea (it was Bob wasn’t it?), i.e., if it isn’t Condition 2 or Condition 3, then maybe it is: normal. Not perfect, but the idea has merit.For what it is worth....

Get a sneak peek of the all-new AOL.com.

[Guest guest]

Ms. Bobbins:

I am sorry....Did you ask me a question(s)? I’m not sure.

Let me ask.....Is your home sterile? Do you never have bread that goes moldy? Have you never have an orange with a big green spot of penicillin? Ever take a swab sample from the bottom of your shoes and have it cultured?

Fact is....Our dwellings are not sterile and we have things that get moldy. Moreover, in my opinion, a certain amount of hazardous agents in our environment is beneficial. Do you recall the discussion on IEQuality not so long ago where an article was posted regarding children growing-up in rural (dirty) environments seem to, as a group, have healthier immune systems than children growing-up in a urban/city environment? It was postulated because of low dose exposure to harmful agents. Including mycotoxins. I concur. It is termed Homeopathy; a term which I believe you are familiar with, or at least you should be. Mold spores specifically linked to causing health problems are part of our natural environment; some more and some less. I can accept that fact. I can also accept reasonably anticipated concentrations of these critters in most locations.

I have seen some very sad situations where families are living in squalor and filth; much more than I would tolerate. Yet, they seem to show no signs of being sick or unhealthy; and these folks are just happy to have a roof over their heads and food on the table. I have also seen situations where families are living in REALLY clean conditions, much more than I would care to labor over, and they seem sick, have allergies, and have other health issues. I am not trying to make any broad generalities or to say that there should be, or is, any norm. However, the “best interest of the health and safety of the occupant” is a relative term. Similarly is “normal” amounts of mold found in homes. You and I probably differ on what constitutes “acceptable.” That’s OK with me.

“Normal” is relative and fluid and changing. Tis why I prefer: anticipated trappings, because it takes into account the characteristics of the circumstance. I am not trying to imply anything, but poor housekeeping is relative. As is REALLY good housekeeping.....and spraying the air with Lysol, and deodorizers plugged into every wall socket, and constant vacuuming of the carpets, and other yucky stuff.

I’m not sure.....did I answer a question?

,

You want to attribute " contamination " as per IICRC's S520 to be due to " housekeeping issues " and accepted as " normal " amounts of mold found in homes? I am referencing your statement below in your post to mean inclusion of molds with the types of spores more specifically linked to causing health problems.

So I ask you, what part of this do you consider to be in the best interest of the health and safety of the occupant? The part that would establish acceptable levels of mycotoxin producing molds to be in homes? Or the part where you imply that these " normal " levels of spores found in homes are due to poor housekeeping skills?

As to what is an acceptable amount of " biology " within a home, please do not attempt to casually throw molds into this unknown equation and mix of yours as to what you construe to be " normal. "

Bobbins, RN, L.Ac, QME

I for one, believe that some biology indoors is normal, it should be accepted as normal, and it should be a housekeeping issue – not representative of “contamination” as mentioned in IICRC’s S520. Drawing the line as to what is acceptable in your house, versus my house, versus Doe’s house, is the “crux of the biscuit” (to quote Zappa). Modern society has been lead to believe the Lysol commercials that the home should be free of germs, bacteria and mold, and be made to smell “Lysol fresh.” Choke!...Gasp!.....Yeah right!, and all the chemicals that go along with Lysol too. Does the IICRC do us a favor defining: normal fungal ecology,.....not sure, but it is a start. I sort of like Bob’s idea (it was Bob wasn’t it?), i.e., if it isn’t Condition 2 or Condition 3, then maybe it is: normal. Not perfect, but the idea has merit