Re: Too Much Stachy?

[Guest guest]

As a mold inspector once explained it - If you had plutonium in your house,

would you really care how many ounces were present or the half life of the

material? So why waste thousands of dollars testing the levels and species of

mold present when you already know that remediation is necessary?

Lab testing does little towards identifying the source for the mold growth and

nothing to remedy the problem. Testing generally only benefits the inspector and

the lab - $$$.

Will

>

> In our experience, one of the hallmarks of the " toxic mould charlatans " is

what we call " playing the numbers game. "

>

> In one of my lectures, I teach the participants how toxic mould con-artists

play games with sample results and use the data to frighten a recipient with the

intent to separate them form their money during a " remediation. "

>

> So, when we look at a " result " of " 7,000,000 spores per gram, " the first

observation is that the units, regardless of the value, is not germane in

determining whether a structure has a problem and the result cannot be used to

speak to the degree or the significance of a possible problem.

>

> For example, a seven story office building could be entirely devoid of a water

problem, or a mould problem, and yet could have a single dime-sized colony of

Stachybotrys in the basement on a single sheet of drywall. The colony could

have been on the dry when it was installed.

>

> A " certified mould inspector " could then sample the single colony and announce

to their client that this is an ENORMOUS number! OMG! The building has mould

and everyone is going to die! (Which of course is completely and objectively

true, but again, it does not speak to the issue of whether or not the building

has a mould problem, and does not speak to the issue of whether remediation is

necessary.)

>

> So now we see single dime-sized colony with a legitimate laboratory report of

7,000,000 spores per gram. The colony weighs in at a whomping 0.1 grams.

Therefore, there are 700,000 spores for dispersal. The seven story office block

has an internal volume of 8,000 m3. Therefore, if the spores hit the HVAC

system, and are evenly dispersed throughout the building, this amounts to an

initial human exposure of 87 spores per cubic meter of air. Let's say just 20%

of those spores are precipitated in the HVAC system before dispersal – that

leaves 70 spores/m3.

>

> Many spores, will settle onto various surfaces (filtering through carpets,

etc), so let's say another 5% is thus removed from the exposure chain, leaving

approximately 66 spores/m3.

>

> Now, considering that the property is under positive pressure with an

industrial HVAC, we know the structure has a good mixing factor (the " k " value),

and will be about 0.7; but let's be conservative and say it's only 0.3 The HVAC

system for the structure ensures 4 ACH, but let's say the re-circ is running at

100% capacity and therefore, there is actually only 2 ACH. We know the

contaminant will exhibit an exponential decay with time (see for example,

Wadden, R.A.; Scheff, P.A., INDOOR AIR POLLUTION: Characterization, Prediction,

and Control Wiley-Interscience Publications, 1983), and as such, by the 8th

minute, the exposure is less than one Stachy spore per cubic meter.

>

> So, the reality is that although 7,000,000 spores per gram may impress the

uneducated punter, in fact, it's hardly worth a yawn, and not something that a

rational person is likely to throw a lot of money after.

>

> Now for those of you who think the above scenario is unreasonable, I can say

that in my experience, we encounter this kind of situation on at least a monthly

basis (in fact, I just got a new legal case in Delaware a few months ago where

this is the situation).

>

> But let's say for fun, an entire 8X4 piece of wallboard is involved, and the

workmen careless, and recklessly smash it to pieces and release ALL the spores

and the initial concentration in the structure is 133,000 Stachy spores/m3. We

see that after 21 minutes, the exposure is once again less than one spore per

m3. OK.. TEN pieces of contaminated wallboard are smashed to smithereens…

wallboard since it is an exponential decay, we hit our one spore/m3 after 25

minutes.

>

> All of this notwithstanding, let's look at the actual anticipated exposure

toxicologically. If we consider the LOAEL for trichothecenes reported the by

the European Commission Health & Consumer Protection Directorate-General, and we

plug in the mycotoxin concentrations actually measured by Brasel, et al

(Applied And Environmental Microbiology, Nov. 2005, p. 7376–7388), we see that

we see that we can equate 8.1E-11 mg trichothecene per spore, and let's just say

the HVAC system crashed immediately after if has distributed the spores released

from 100 pieces of smashed up 8X4 wallboards all at once and NONE of the spores

get removed by exfiltration, that leaves us with approximately 13,000,000

spores/m3 of human exposure – even at THAT levels, the human exposure is 28

times LOWER than the lowest concentration known to create an health hazard.

>

> And this, folks, is what happens to the " run-around-with-your-hair-on-fire "

toxic mould hype, when viewed by a scientist. So…. 7,000,000 spores/grams?

Yawn. I would recommend that the building owner hire a consultant who actually

knows something about mould and remediation, they may also like to read the

following discussion:

>

> http://www.forensic-applications.com/moulds/remediation.html

>

>

> Cheers!

>

> Caoimhín P. Connell

> Forensic Industrial Hygienist

> www.forensic-applications.com

>

>

> (The opinions expressed here are exclusively my personal opinions and do not

necessarily reflect my professional opinion, opinion of my employer, agency,

peers, or professional affiliates. The above post is for information only and

does not reflect professional advice and is not intended to supercede the

professional advice of others.)

>

> AMDG

>