Stachy

[Guest guest]

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You touched on something I too find puzzling......Stachy goes very well on the paper coating on sheetrock, on cardboard, and on many other recycled paper products. Stachy does not appear to grow well on virgin cellulose; be it wood or wood sawdust. It also does not grow well on white (writing) paper, but it grows really good on newspaper (a recycled pulp). This said, I believe that there is something about the treatment and sizing process of paper pulp that seems to be beneficial to Stachy germination and growth. Is it the chemical process of pulp processing? Is there something in cellulose pulp that is removed which allows Stachy to take hold so quickly, or is it something they add (e.g., a sizer, a binder, a????) which is a grow enhancer – though it is probably not intended as such.

Steve.....I have some info coming from US Gypsum that you will find interesting regarding the manufacture of sheetrock that may answer your question.....Is Stachy in the paper pulp?

Regarding air sampling and finding Stachy......Most folks who say they do not find many Stachy spores (e.g., one in a thousand) I find base this observation primarily samples collecting 75 liters of air using A-O-C cassettes or a similar media. 75 liters of air is a very very small sample. 150 liters of air is a small sample. If one were to routinely collect 500, 750, 1000 liters of air, many more Stachy spores will be collected. Moreover, labs are reporting results as spores per cubic meter of air, so why not collect a cubic meter of air? Why are we collecting only 7.5% of a cubic meter?. Stachy spores are also often combined with other airborne detritus, in bundles and in matrixes. I have seen many more Stachy spores in combination with other stuff, than I have seen solo. Does this mean that they are there but they are missed? Are conventional sampling methods missing the big, fat, sticky spores because they are associated with other particulates? I don’t know, and depending upon who you ask, the answers are really different.

What I do know is....

The biggest damn reservoir for naturally-occurring Stachy is the soil.

Rinse the bottom of your shoes, culture the rinsate, and your will often find lots of Stachy colonies.

Stachy is not as prevalent in the air as other, smaller, drier spores, but they are there.

Anyone who thinks that Stachy is only located in wet conditions, or is only present in the air after a rain, is mistaken.

Anyone who thinks that Stachy is only found in wet parts of the country is mistaken; they don’t know their soil microbiology.

I takes a lot of air to see the Stachy spores and A-O-C sampling is not the best method.

If you run multiple bio-aerosols samplers simultaneously, using the same media, at the same flow rate, and all of them in the same location – sucking the same air, the results can be profoundly different....why?

Regards,

Your point about only finding Stachybotrys in an outdoor sample once out of thousands of samples collected in the Philadelphia area is interesting. Here in Sacramento I am finding it in about one in 50 outdoor samples.

I seem to remember Dotson had a paper on the prevalence of Stachybotrys in outdoor air that was about twice what I’ve been seeing here.

I would like to hear what other consultants are experiencing.

Also, I have never identified Stachybotrys growing under a sill plate either wood to wood or wood to concrete contact. Whenever I have identified Stachybotrys on wood, it has been transferred from growth on paper (i.e. gypsum paper in contact with the wood).

Does anyone have experience to the contrary?

Thanks

Banta