PNNL

Abstract

Objective: The objective of this study was to develop screening tools that could be used to estimate the mold burden in a home which would indicate whether more detailed testing might be useful. Methods: Previously, in the American Healthy Home Survey, a DNA-based method of analysis called mold specific quantitative PCR was used to measure 36 molds in standard protocol dust samples. This resulted in a national index called the Environmental Relative Moldiness Index. In this current study, two possible screening methods were considered: use of the vacuum cleaner bag dust rather than the standard protocol dust samples and reducing the number of molds needed to be quantified resulting in the creation of a simpler mold burden scale. Results: Comparison of vacuum bag and standard dust samples from 157 of the same homes demonstrated that most molds had higher detection rates in vacuum bag dust compared to the standard dust samples but the ERMI values were still related to each other. The second approach to simplifying the screening for mold burdens produced a correlated (?=0.80) index to the ERMI called the American Relative Moldiness Index (ARMI) which requires the analysis of only 12 species. Conclusions: Vacuum bag dust sample ERMI values were predictive in placing a home into the lower or upper 50% of homes on the ERMI scale. If it is not possible to obtain the standard dust sample, the vacuum cleaner bag dust may be a useful screening tool for estimating mold burdens in homes. If the standard sample is available and a simpler screening test is sought to estimate the mold burden in homes, the ARMI scale might be useful.