Citation:

VESPER, S. J. UNDERSTANDING AND APPLYING ENVIRONMENTAL RELATIVE MOLDINESS INDEX - ERMI. Presented at National EPA-Tribal Science Council Meeting, Chicago, IL, April 03, 2007.

Impact/Purpose:

1. Develop and publish a standard method or guidance document for QPCR analysis of microorganisms in environmental samples (air and water filtrates and dust).a standard method or guidance document for QPCR analysis of microorganisms in environmental samples (air and water filtrates and dust). Publication will involve a consensus standards organization. 2. Use QPCR methods to monitor childhood exposures to mold as a part of field studies, in order to establish whether a relationship exists between molds encountered in indoor environments and asthma-related health problems.

Description:

This study compared two binary classification methods to evaluate the mold condition in 271 homes of infants, 144 of which later developed symptoms of respiratory illness. A method using on-site visual mold inspection was compared to another method using a quantitative index of moldiness, calculated from mold specific quantitative PCR (MSQPCR) measurements on the concentration of 36 species of molds in floor dust samples called the EPA relative moldiness index© (ERMI©).

The binary classification of homes as either moldy or non-moldy by on-site visual home inspection was not predictive of the development of respiratory illness (wheeze and/or rhinitis) (p = 0.27). Conversely, a method developed using the ERMI© index fit to a logistic function, can be used to predict the occurrence of illness in homes and allows stake-holders the choice among various levels of risk. An example is given where an ERMI© value of -4.29 is used as a threshold for binary classification of homes producing an odds ratio of 2.53 (95% confidence limits of 1.35, 4.77). The ERMI© based method provides a new and more flexible platform to support mold remediation decisions based on quantitative estimates using cost and risk tolerance.

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