Is it my home?

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Start with the water

Mold grows where water has been. Active growth needs a moisture source, which is why a visual inspection and a moisture map usually tell you more than a sample does. If the source is still there, the testing is measuring a moving target.

 

What to test

ERMI (Environmental Relative Moldiness Index). A DNA analysis of settled dust that measures 36 mold species in two groups: those tied to water damage and those common everywhere. It began as an EPA research tool, and clinicians who follow the Shoemaker protocol use it to gauge the history of water damage in a space.

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HERTSMI-2. A shorter score drawn from five of the ERMI species, built to flag the molds most associated with relapse in mold-sensitized people.

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How to use them. ERMI and HERTSMI-2 are contested. The EPA has not validated ERMI for routine use in individual homes, and many remediators dispute it. Collection method matters, and a freshly deep-cleaned home can score worse because the cleaning removes the dust that balances the ratio. Treat a score as one data point next to an inspection, never as a pass or fail.

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Air sampling (spore traps). A snapshot of one room on one day. Useful for comparing indoors to outdoors, limited as a stand-alone answer.

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How the home matters by condition

 

Mold illness. The exposure is the driver, so removing it comes before anything else in the plan.

CIRS. In people with the susceptible genetics, ongoing exposure keeps the inflammatory response running. The Shoemaker sequence starts by getting out of the exposure, and treatment follows.

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MCAS. Mast cells respond to many triggers, so the home matters beyond mold: fragrance, cleaning products, humidity swings and dust all load the same system. Mold and MCAS overlap often enough that clinicians who see one look for the other.

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Other chronic illness. A damaged building is often one load among several. Checking it early removes one variable before you interpret everything else.

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*This page is education, not medical advice. Testing decisions belong with your treating clinician.