ERMI is a molecular based test that is being pushed by a select few labs, doctors and some allied health practitioners and water damage assessors as the latest and best method to quantify human exposure to mould. The test stands for the Environmental Relative Moldiness Index and although it's been patented by the U.S. Environmental Protection Agency it has not been validated for public use.
In fact the EPA has made is very clear that labs should not be selling this at all to consumers!
There should be warning bells sounding if you have been encouraged to use this test or if your clinical outcome or insurance or indoor air quality case has been determined using ERMI.
Take a look at the documents that highlight the risks from this technology and make up your own mind.
- Report: Public May Be Making Indoor Mold Cleanup Decisions Based on EPA Tool Developed Only for Research Applications
Report #13-P-0356, August 22, 2013
- The Environmental Relative Moldiness Index: A Research Tool Fact Sheet
There is nothing that ERMI can do that traditional indoor air quality metrics like spore traps and viable sampling can't already do with far greater accuracy.
In closing, it is also important to note that a very recent paper has also flagged the very real risk that molecular methods may not in fact identify what they are supposed to be identifying.
- Ten reasons why a sequence-based nomenclature is not useful for fungi anytime soon. Source: IMA Fungus, Volume 9, Number 1, June 2018, pp. 177-183(7)
The ERMI method is also expensive and reductionist in that reports are often based on a single sample collected across multiple rooms of a home. This means there is use of non-uniform sample size collection and a host of other methodological problems.
Interpretations can be misleading and extrapolations commonly ignore the small study effect and the inherent lack of statistical analysis or significance testing. The entire point of indoor air quality testing and water damage inspections is to use collected data to practically inform the occupants on how best to remediate water damaged areas. Tests like ERMI therefore don't determine an accurate exposure history to mould.
The fact remains that even if ERMI does red flag a mould problem this does not easily allow the occupants to know which area(s) to remediate since the units of measure are not compatible with other established indoor air quality tests for mould and methods for visual inspection that do have standards and guidelines for interpretation.
The academic literature also backs up these concerns. A recent paper published in the European Respiratory Review looked at the results on ERMI where they "studied its association with asthma: the authors concluded that the ERMI studies do not prove that there is a causal relationship between mould exposure and the development or exacerbation of asthma". [Source: Caillaud, D., Leynaert, B., Keirsbulck & Nadif, R. (2018). Indoor mould exposure, asthma and rhinitis: findings from systematic reviews and recent longitudinal studies. Eur Respirator Rev. 27: 170137].
All up, the public should be very skeptical about ERMI and stick with tried and true mould testing methods until further notice.