Re: Biomechanics of conidial dispersal in the toxic mold Stachybo...

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Tony, ("Tiny"????) You misspelled your name when signing off LOL

I can't believe it. We finally agree on a paper.

I like this paper, too. I think it makes a couple of very important statements:

1. That perhaps we should rethink the use of industrial fans when drying out damp areas where mold is already known to be present. Wonder if that would include negative air machines?

2. That HVAC's could well be a major contributor to the problem because of the known increased/forced air flow.

3. Like you say "The Data also imply (on the force data - nice work, takes me back to college) that hand-to-mouth where visible mold is present could be a risk" (So inhalation is not the only route of exposure of concern)

4. To quote from the paper: "We assume that the quantity of airborne mycotoxins increases in proportion to the area of mold growth in a particular indoor space, but it is difficult to quantify the extent of mold proliferation in situations where multiple discrete colonies are distributed over a wide area. Despite these uncertainties, the suggestion by Burge (1996) -- and supported by Kelman et al. (2004) -- that a person living in a highly contaminated environment could accumulate no more than a few nanograms of toxin in 24 h seems very reasonable. The significance of this level of mycotoxin exposure remains uncertain." .....which is a far cry from using Kelman's extrapolations to profess it is scientifically proven "highly unlikely at best, even among the most hypothetically vulnerable of subpopulations" and that claims of illness are only "a result of trial lawyers, media hype and Junk Science".

5. "The ejection of microparticulates from toxigenic colonies may boost the concentration of airborne mycotoxins beyond estimates based on conidial release" The paper acknowledges other factors coming into play.

6. This paper appears to be consistent with the IOM regarding what can and cannot be proven from these types of studies: From the IOM “Toxicologic studies, which examine such responses using animal and cellular models, cannot be used by themselves to draw conclusions about human health effects.â€

This paper causes me to have a question, though. So could one surmise from this that mold releases it's toxins when first disturbed and then when left undisturbed it "regroups" and produces more toxins in preparation for the next attack against it?

Also, it a small world, indeed. Nik Money was one of four handing out diplomas this past May as my youngest walked across the stage at a very small college in the Midwest, Miami U. I saw him laugh as she and her three girlfriends walked by, wearing outrageous neon sunglasses. He told me later that he definitely remembered my daughter out of about 1800 graduates.

Sharon K

"0.3–1.6 ms-1"

In industry settings, (heavy engineering to labs and warehouses with people working) 50% less than 0-0.1 m/s and 85% of measurements were <0.3 m/s (GM 0.06 m/s). (very very few over 1 m/s) and to quote the author - " general wind speeds in the workplace are higher than those found in offices or homes" (Baldwin, 1998)

4. Stachy holds on tight:

"Colonies of S. chartarum were battered by airspeeds of

0.3–1.6ms-1 within the microXow apparatus. Conidiophores

showed considerable elasticity, moving backwards

and forwards in the airstream, pivoting through angles of

up to 45° (Fig. 3). Individual conidia were firmly fixed to

one another within their conidial heads (clusters), and the

heads showed strong attachment to their supporting conidiophores.

Only in rare instances did we observe conidia separating

from their conidiophores."

6. Data here is comparable to other papers I have, but not as well done.

7. The data to me do not suggest large releases to breathing zones in typical house usage, but possibly bursts where visible mold is present and disturbed. Very much suggests that remediation should be done carefully with proper precautions.

8. The Data also imply (on the force data - nice work, takes me back to college) that hand-to-mouth where visible mold is present could be a risk. I have done some calculations and found this to be a possible source of significant exposure.

9. Incidentally, I really like the paper - good engineering style thinking, matches a paper for the early 60s. It was authored by Jim Tucker's (EMS) daughter. Jim supplied the sampling equip.

Tiny

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[Guest guest]

> 5. " The ejection of microparticulates from toxigenic colonies may

boost the concentration of airborne mycotoxins beyond estimates

based on conidial release "

>

Here's another " Blast from the past " .

-MW

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Date: Wed Jun 25, 2003 5:15 pm

Subject: Re: [sickbuildings]Thunder storms and fungal spores

erik_johnson...

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I posted this in April but nobody seemed to notice.

-

When does the toxin come out to play?

At times of barometric pressure change.

The spores seem to be constantly building up internal pressure so even

though they're always popping a certain number, they're primed to

release a staggeringly higher amount when the barometric pressure has

a sudden drop. Kind of like a bunch of balloons that are blown up as

much as they'll take and then you put 'em in the back of your minivan

and drive quickly up a hill. BLAMMO!

That, I think is why people complain so much about " change in the

weather " and being able to sense a barometric pressure change.

'Snot the air pressure - it's the mycotoxin release.

At least it is for me.