EDIT: Can't Speel

[Guest guest]

Let me share an article with you that Randy Penn

http://www.InspectorPenn.com wrote for my site last year.

I think that if you will read it, it will put some things into

perspective.

http://www.startremodeling.com/mycotoxins_voc.htm

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Mold: Volatile Organic Compound's

& Mycotoxins : A Primer for Homeowners

by R.L. Penn August, 2001

Introduction

You can find a lot of information on mold, but trying to understand

it may be difficult to those who didn't take biology and

chemistry.Even after stumbling through the pronunciation of these

words, not everyone can comprehend what was meant by the statement.

" Satratoxin, a low-molecular weight non-volatile organically derived

agent, belongs to the macrocyclic trichothecene class of mycotoxins

generated from fungal microorganisms. "

As an aid to the homeowner, this overview is intended to explain a

few bad products of mold in a less scientific manner. It will focus

on those types of mold that have been considered as problematic to

the " indoor mold issue " and does not address other fungal organisms

which may behave differently. Analogies presented are not intended to

be scientifically accurate, but rather to illustrate complex

behaviors in more simple terms.

The people who study mold (mycologists) have identified and described

over 100,000 species and many believe that this is only a partial

listing (estimates of 1.5 million species have been suggested). Try

jotting down the names of the first 100,000 people you know then

describe each person's behavior in a specific setting. You will begin

to understand the complexities of the problem facing these mold

professionals.

Most people have associated mold with allergies and these reactions

are certainly prevalent with most all species found indoors. In

addition to causing an allergic response, molds can be irritating,

infectious and even toxic to humans. Understanding the general

behavior of mold provides insight into the adverse components

produced by mold.

The Organism

Fungi can be considered nature's garbage disposal. Without them, the

term " biodegradable " would not be so significant to our planet and we

would have mountains of leaves, dead trees, and other organic

materials sitting around…all deposited since the beginning of time.

This, in simple terms, is the `why' of mold.

For the moment, think of mold as a weed. This weed has a root system,

a vegetative stalk, and a seed pod. For mold, the root system is made

up of hyphae (high-fee). As hyphae grows into a mass during the

vegetative state, it becomes a mycelium (my-sill-ee-um). The spores,

designed for reproduction, are similar to seeds.

Like a weed, mold needs food and water to survive (yes, both need

more than that, however, we are simplifying things here). For mold,

the food of preference is organic matter (things that once were

living). Indoors, those things are wood, paper, organic dust and

dirt, leather, skin flakes, body oils, etc.

When mold spores that are floating around in the air land on a food

source, they sit there patiently waiting for water. If the item they

land on should contain sufficient moisture, or water comes from

another source (leaks, etc.), the spore germinates and hyphae grows.

The hyphae branch out, secrete enzymes to breakdown the food, form

the mycelium, and absorb nutrients to grow. As long as the food and

water hold out, colonies will continue to grow. Note that individual

hyphae and spores are very, very small and few can see them without a

microscope. When you see visible mold, you are generally seeing that

mass of mycelium.

Hyphae can intertwine into the fibers of the substrate, penetrating

the pores. As it consumes the substrate, it can also create it's own

route by dissolving pathways into the material. This is one of the

reasons it is so difficult to kill and/or clean up mold on organic

substrates. If you remove the surface growth, those bits of hyphae

within the substrate are ready for re-growth upon the return of

moisture.

As the organism matures, it develops spores intended for

reproduction. Spores vary in size, shape, weight and methods of

distribution. Some are light and buoyant so they float easily through

the air. Others are wet and sticky and may cling to insects, rodents,

etc. as a mode of travel.

Volatile Organic Compounds

As mold " consumes " it's food, the chemical reactions of enzymes,

substrates and mold growth produce carbon dioxide, water, and

volatile organic compounds (VOC's). Because these items are a result

of actions essential to the growth of the organism, they are

classified as primary metabolites.

For mold, many types of VOC's are produced and typically include

aldehydes, alcohols, keytones, and hydrocarbons. They have complex

structures and names like " 2-methyl-1-propanol " , so if you are going

to dig deeper into VOC's, get ready for chemistry class.

They are called volatile in that they evaporate easily at room

temperature and pressure. Fortunately, this volatility aids in

dilution with fresh air to minimize concentrated build-up of these

chemicals. Testing for VOC's is often accomplished by using vacuum

cylinders to obtain samples of the air with laboratory analysis

obtained from sophisticated test instruments (gas chromatograph/mass

spectrometer).

When you smell a " musty-moldy " odor, it's generally the VOC's you are

noticing. VOC's are often considered irritants to mucus membranes,

however, are also capable of both short-term and long-term adverse

health effects. If you do smell these odors, it's a sure sign the

mold is consuming and growing and you need to take action. (Note that

VOC's may also be derived from non-mold sources including natural

materials used in cleaning agents.)

Toxins

Many molds are capable of producing compounds called mycotoxins which

are toxic to other organisms, including people. Mycologists believe

these toxins are produced as protection against competing organisms

and therefore, humans are simply caught in the cross-fire of this

fight for survival.

Since these toxins are not essential for growth, they are classified

as secondary metabolites. Toxic secondary metabolites require extra

work on the part of the organism so production does not occur at all

times, or, with all types of mold.

Scientists have identified over 400 mycotoxins and unlike VOC's,

these compounds are usually non-volatile (don't evaporate easily at

room temperature and pressure). One strain of mold may produce

multiple toxins and one type of toxin may be produced by multiple

strains of mold. Research has indicated that the type of substrate

(nutrients), the growing conditions, together with the species of

mold, will impact which toxins are created.

Some of these toxic substances are considered extremely hazardous to

people, unfortunately, quantified human dose-response data is

limited. Lab and field studies have shown these compounds to produce

severe toxic effects in both animals and humans and therefore, the

general recommendation is to minimize exposure to potentially

toxigenic mold. Symptoms from toxic exposure range from flu-like

symptoms, skin rashes and lesions, bleeding, fatigue, difficulty

breathing, depression, etc. to longer-term nerve and organ problems,

altered immunity, and cancer.

Not all secondary metabolites are considered bad for people…the

antibiotics such as penicillin have beneficial use. However, from the

mycological standpoint, antibiotics are considered mycotoxins since

they too are generated by mold to ward off microorganisms (i.e.

competing bacteria).

When the organism is producing toxins, the toxins are known to be

present in the cell wall of spores and hyphae. It's relatively easy

to test for spores and hyphae, however, testing these components to

see if they contain toxins is significantly more complex. Whereas a

single spore can be viewed under a microscope, identifying what

compounds are contained in the cell wall is difficult.

In order to identify these toxic compounds, laboratories must have a

sufficient quantity of toxin-containing spores and carefully process

them through sophisticated and expensive equipment that is capable of

isolating chemicals down to billionths of an gram (remember, mold

spores are microscopic so what is contained within it's cell wall is

extremely small). This testing is made even more difficult since

there are a few hundred toxins to analyze and the behavior of mold is

such that a toxin-producing mold in the field doesn't necessarily

produce the same type and quantity of toxins in the lab.

Generally speaking, identifying a mold type that is known to be

capable of producing toxins is sufficient information to warrant

precautions and avoid exposure without submitting for toxic analysis.

However, if trying to confirm specific adverse health effects,

obtaining an analysis of both VOC's and toxins can be beneficial but

often expensive.

Randy Penn is an independent licensed real estate inspector (Texas

#5491) who specializes in mold testing and specimen recovery. He has

a Bachelor of Science degree in engineering, is a member of the

Indoor Air Quality Association, has invested hundreds of hours in

researching and training on fungal microorganisms, has completed

IAQA's workshop on mold remediation and has provided mold related

presentations to homeowners and real estate professionals.