Decoding Your ERMI and HERTSMI-2: A Practical Guide to Mold Testing Results

Introduction: Is the Air You Breathe Hurting You?

You've taken the crucial first step: testing your environment for mold. Perhaps you've been battling unexplained fatigue, persistent respiratory issues, or that nagging feeling that something in your home or workplace just isn't right. Maybe your doctor, familiar with the complexities of mold-related illness, recommended testing. Or perhaps you’ve just become aware of how common mold is in indoor environments, and want to understand how it might be affecting your health.

Whatever your reasons, you've now received your ERMI or HERTSMI-2 report, and you're staring at a list of scientific names and numbers that might as well be a foreign language. Don't worry – you're not alone! These tests, while incredibly valuable, can be intimidating without a guide. This article is your decoder ring, designed to help you understand what those results mean and, more importantly, what to do with that information.

The Environmental Relative Moldiness Index (ERMI) and its focused counterpart, the Health Effects Roster of Type-Specific Formers of Mycotoxins and Inflammagens (HERTSMI-2), are powerful tools in the fight for healthier indoor environments. But like any tool, they're only as good as your understanding of how to use them. This isn't just about lab results; it's about taking control of your health and creating a safer space for yourself and your loved ones.

Section 1: Understanding the ERMI: A Snapshot of Your Home's Mold History

The ERMI, developed by the U.S. Environmental Protection Agency (EPA), is more than just a mold test. It's a window into the history of mold in your home. Think of it like this: dust, over time, becomes a sort of "environmental diary," accumulating traces of what's been floating in the air. The ERMI analyzes that dust, using a sophisticated DNA-based method called Mold-Specific Quantitative Polymerase Chain Reaction (MSQPCR), to identify and quantify 36 different mold species.

1.1 What Exactly Does the ERMI Test For?

The ERMI doesn't just tell you if mold is present; it tells you what kinds and how much relative to other homes. The 36 molds are divided into two groups:

• Group 1: Water Damage Molds (26 species): These are the troublemakers, the species most commonly found in water-damaged buildings. Think of them as the "usual suspects" in mold-related health issues.
• Group 2: Common Indoor Molds (10 species): These molds are more widespread and often found even in homes without significant water damage. They're generally less concerning, but high levels can still be problematic.
  

1.2 Decoding the ERMI Report: It's All About the Math (But We'll Keep It Simple!)

The ERMI report can look daunting, with scientific names like Aspergillus fumigatus and Stachybotrys chartarum. But the core concept is a simple subtraction problem. The lab measures the concentration of each mold species in your dust sample (expressed as spore equivalents per milligram of dust). These values are then converted to logarithms (don't worry, the lab does this for you!).

Here's the magic formula:

ERMI Score = (Sum of Logs of Group 1 Molds) - (Sum of Logs of Group 2 Molds)

Essentially, the ERMI score reflects the balance between the "bad" water-damage molds and the "common" molds. A higher ERMI score suggests a greater likelihood of past or present water damage and a higher mold burden.

1.3 What's a "Good" ERMI Score?

This is where it gets a little tricky. There's no single, universally agreed-upon "safe" ERMI score. The original EPA research used an ERMI scale ranging from roughly -10 (very low mold burden) to 20 (very high mold burden). They compared these scores to a database of over 1,000 homes across the U.S.

Here are some general guidelines, but always interpret your results in consultation with a mold-literate professional:

• Less than 2: Generally considered a low mold burden.
• 2 to 5 : Can vary. Discuss these results with your health care provider.
• Greater than 5: In the top 25% of homes tested in the US EPA study, a score this high is cause for concern.

Important Considerations:

• Individual Sensitivity: People react differently to mold. Someone with a genetic predisposition to mold-related illness (like those with certain HLA-DR genotypes) might experience symptoms even at a lower ERMI score.
• Total Mold Load: Even "common" molds (Group 2) can contribute to health problems if present in very high quantities.
• Specific Mold Types: Certain molds, like Stachybotrys (often called "black mold"), are considered more toxic and concerning, regardless of the overall ERMI score.

Section 2: The HERTSMI-2: Focusing on the Most Worrisome Molds

The HERTSMI-2 is a more focused test, developed by Dr. Ritchie Shoemaker, a pioneer in the field of mold-related illness. It zeroes in on five specific mold species known to be particularly problematic for human health:

1. Aspergillus penicillioides
2. Aspergillus versicolor
3. Chaetomium globosum
4. Stachybotrys chartarum
5. Wallemia sebi
   

2.1 Why These Five Molds?

Dr. Shoemaker's research, based on thousands of patients with Chronic Inflammatory Response Syndrome (CIRS), identified these five molds as having a strong association with adverse health effects. They are potent producers of mycotoxins and other inflammatory substances.

2.2 The HERTSMI-2 Scoring System: A Simple Point System

The HERTSMI-2 uses a simple point system based on the concentration of each of the five molds in your dust sample. Each mold is assigned points based on its concentration range.

The points for each mold (based on how many of each are present) are added up to give you a total HERTSMI-2 score.

2.3 Interpreting Your HERTSMI-2 Score

Here's a general guideline for interpreting HERTSMI-2 scores, but always discuss your results with a qualified professional:

• Less than 11: Considered a lower risk, statistically safe for re-entry after remediation for those with CIRS.
• 11-15: Borderline. Further investigation and cleaning are recommended.
• Greater than 15: Considered a higher risk, especially for individuals with mold-related illnesses. Remediation is strongly recommended.

Important Note: For individuals with severe CIRS, especially those with very high C4a levels in their blood (a biomarker of inflammation), even a HERTSMI-2 score below 11 might be problematic. Some practitioners recommend aiming for a score below 8 in these cases.

Section 3: Putting It All Together: Using Your Results

Your ERMI or HERTSMI-2 results are not a standalone diagnosis. They are pieces of a larger puzzle. Here's how to use them effectively:

1. Consult with a Mold-Literate Professional: This is crucial, whether you're a homeowner or a renter. A healthcare provider specializing in mold-related illness can interpret your test results in the context of your health history, symptoms, and other medical tests. An Indoor Environmental Professional (IEP) can help you understand the implications of your results for your home and guide you on remediation options.
2. Consider Your Symptoms: Do your symptoms correlate with your test results? Do they worsen in certain environments? Tracking your symptoms can provide valuable clues.
3. Don't Panic: A high ERMI or HERTSMI-2 score doesn't mean your home is condemned. It means you have valuable information to take action.
4. Develop a Plan: Based on your test results, your health status, and your living situation, develop a plan. This might involve:
5. Further investigation to pinpoint mold sources.
6. Remediation by a qualified professional.
7. Improving ventilation and controlling humidity.
8. Medical treatment for mold-related illness.
9. Possibly relocating if remediation isn't feasible.

Section 4: Beyond the Numbers: Real-World Examples

Let's look at a few hypothetical scenarios to illustrate how ERMI and HERTSMI-2 results can be used:

• Scenario 1: The Renters

Experiencing persistent fatigue and respiratory problems, renters report mustiness to their landlord. The landlord's inspector performs only basic air sampling, which comes back "normal," leading the landlord to dismiss their concerns. Suspecting hidden issues, the renters independently perform a HERTSMI-2 dust test, yielding a high score (18). They leverage these dust results, reflecting historical contamination, to demand a more thorough assessment from their landlord, challenging the inadequacy of the initial air tests.

• Scenario 2: The Homeowners
  A family notices a musty smell in their basement after heavy rains. They hire a certified mold inspector who conducts an ERMI test. The ERMI score is 12, and the report identifies several water-damage-related molds. They use this information to guide their remediation plan, focusing on fixing the moisture source and removing the contaminated materials.
• Scenario 3: The CIRS Patient
  An individual with a confirmed diagnosis of CIRS is looking for a new home. They use the HERTSMI-2 test to screen potential properties, aiming for a score below 11 (or even lower, based on their doctor's recommendation). This helps them avoid environments that could trigger a relapse.
  

Conclusion: Knowledge is Power

Mold testing, when done correctly and interpreted within the right context, can be an incredibly empowering tool. It provides concrete data to inform decisions about your health and your living environment. Remember, you're not alone in this journey. By understanding the ERMI and HERTSMI-2 tests, working with qualified professionals, and taking proactive steps, you can create a safer, healthier space for yourself and your loved ones.

Next Steps:

• Take the free MoldCo Home & Health Questionnaire to assess your potential risk. [Link to Questionnaire]
• Explore The MoldCo for a comprehensive set of products to support your health. [Link to Products page]
• Consult with a Mold-Literate Doctor: If you suspect mold is impacting your health, seek out a physician experienced in mold-related illnesses.
• Contact a Certified Indoor Environmental Professional (IEP): If you need a mold inspection or remediation guidance, find a qualified IEP in your area.

References:

• Vesper, S., McKinstry, C., Haugland, R., Wymer, L., Bradham, K., Ashley, P., ... & Friedman, W. (2007). Development of an environmental relative moldiness index for US homes. Journal of Occupational and Environmental Medicine, 49(8), 829-833.
• Shoemaker, R. C., & Lark, D. (2017). HERTSMI-2 and ERMI: Correlating Human Health Risk with Mold Specific qPCR in Water-Damaged Buildings. Proceedings of the 14th International Conference on Indoor Air Quality and Climate, Ghent, Belgium.
• Shoemaker, R.C. (2010) Surviving Mold.
• https://www.uptodate.com/contents/assessment-of-mold-in-the-indoor-environment/print

Disclaimer: This article is for informational purposes only and should not be considered medical or environmental advice.  Consult with qualified professionals for personalized guidance.