Articles on High humidity situations and mycotoxins..

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I just found these and thought they waranted a separate post.

PDF file available at

http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1566214 & blobtype=pdf

Research Article

Microfungal contamination of damp buildings--examples of risk

constructions and risk materials.

S Gravesen, P A Nielsen, R Iversen, and K F Nielsen

Energy and Indoor Climate Division, Danish Building Research

Institute, Horsholm, Denmark. sug@...

Abstract

To elucidate problems with microfungal infestation in indoor

environments, a multidisciplinary collaborative pilot study, supported

by a grant from the Danish Ministry of Housing and Urban Affairs, was

performed on 72 mold-infected building materials from 23 buildings.

Water leakage through roofs, rising damp, and defective plumbing

installations were the main reasons for water damage with subsequent

infestation of molds. From a score system assessing the

bioavailability of the building materials, products most vulnerable to

mold attacks were water damaged, aged organic materials containing

cellulose, such as wooden materials, jute, wallpaper, and cardboard.

The microfungal genera most frequently encountered were Penicillium

(68%), Aspergillus (56%), Chaetomium (22%), Ulocladium, (21%),

Stachybotrys (19%) and Cladosporium (15%). Penicillium chrysogenum,

Aspergillus versicolor, and Stachybotrys chartarum were the most

frequently occurring species. Under field conditions, several

trichothecenes were detected in each of three commonly used building

materials, heavily contaminated with S. chartarum. Under experimental

conditions, four out of five isolates of S. chartarum produced

satratoxin H and G when growing on new and old, very humid gypsum

boards. A. versicolor produced the carcinogenic mycotoxin

sterigmatocystin and 5-methoxysterigmatocystin under the same

conditions.

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http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve & db=PubMed & list_uids=151047\

87 & dopt=Abstract

Indoor Air. 2004 Jun;14(3):196-9.

Wall relative humidity: a simple and reliable index for predicting

Stachybotrys chartarum infestation in dwellings.

Boutin-Forzano S, Charpin-Kadouch C, Chabbi S, Bennedjai N, Dumon

H, Charpin D.

Department of Chest Diseases and Allergy, Hôpital Nord, Marseille, France.

Because the indoor mold Stachybotrys chartarum has been considered

as potentially responsible for serious health effects, its

identification in dwellings with water damages is of utmost

importance. As such dwellings are many, it would be of great value to

have a simple and reliable index for predicting its presence. The aim

of the study was to compare measurements of wall relative humidity

(RH) to mold identification in 458 samples from 100 dwellings. Mold

identification was performed by direct microscopic examination of a

sample collected on the wall by the gummed paper technique. Mean (+/-

s.d.) wall RH (%) was much higher (97.0 +/- 6.1) on the 30 samples

where S. chartarum was identified compared with the 291 samples where

other molds were identified (41.8 +/- 36.9) and to the 137 samples

where no molds were identified (38.9 +/- 34.8). There was no

straightforward relationship between wall and room RH. In conclusion,

this study clearly demonstrate that the simple measurement of wall RH

can be used as a reliable index for discarding and suspecting S.

chartarum infestation in dwellings.

PRACTICAL IMPLICATIONS: This paper suggests that very high relative

humidity (RH) within walls is a strong risk factor for their

infestation with the 'toxic mold' Stachybotrys chartarum. Besides,

data from the literature demonstrate that other molds are able to

produce mycotoxins when RH is very high. Thus, measurement of wall RH,

which is easy to perform and very cheap, could be used as a screening

tool to select those dwellings where mold identification should be

performed and remediation should be promptly carried out.

Publication Types:

* Research Support, Non-U.S. Gov't

PMID: 15104787 [PubMed - indexed for MEDLINE]

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Thanks Live, great find