The Environmental Relative Mold Index (ERMI) was developed by the United States Environmental Protection Agency (EPA) scientists as a tool for estimating the amount of mold in buildings. As a research tool, it can be used to estimate the amount of mold and to identify some of the types of mold present in dust samples. While the ERMI is gaining popularity as a tool for mold investigation in buildings, it has yet to be validated for non-research use. For this reason, the EPA does not recommend routine public use of ERMI in homes, schools, or other buildings.
Why ERMI should not be solely relied upon for mold assessment
Though the ERMI may seem like a convenient, objective, and advanced technology for assessing mold contamination in buildings, its critics point out several reasons why it should not be solely relied upon for mold assessment.
Some of the the reasons include:
1. Limited scope: ERMI does not cover the full spectrum of potentially harmful mold species. There are many types of molds that can cause health problems and structural damage to the building that ERMI does not consider.
2. No consensus: There is no consensus among experts and scientific community on the validity and reliability of ERMI as a mold assessment tool. While some studies suggest a correlation between ERMI scores and mold-related health problems, others question their accuracy and usefulness.
3. Inadequate sampling methodology: ERMI relies on house dust samples to assess mold contamination. This method, however, has limitations. Mold contamination can be localized and may not be evenly distributed throughout the dust in the home. This means that results from a single dust sample may not be a good representative of mold contamination levels throughout the building.
4. Difficulties in Interpretation: the ERMI results are often presented as a single numerical value, which can be misleading. Various factors must be considered when interpreting this value, such as the specific type of mold detected, the location and extent of mold growth, and the individual’s susceptibility to mold-related health problems. Without appropriate expertise, it can be difficult to draw accurate conclusions from ERMI results.
5. Lack of standardization: The ERMI calculation formula and the interpretation guidelines have not been generally standardized. Different laboratories may use different reference methods and databases, leading to inconsistent results. This lack of standardization affects the comparability and reliability of ERMI results from different laboratories.
In summary, while the ERMI may be useful as a complementary tool in mold investigations, it should not be used alone for mold assessments.
