by Jennifer Shea
Posted 3/30/20

Mold can be a year-round problem, but early spring is the unofficial beginning of “mold season,” when April showers and rising humidity levels create a prime moist environment for mold growth across the country. And for those who have mold in their homes — and the vast majority of us do have some level of growth — it might be particularly problematic this year if you’re sheltering in place in response to the COVID-19 crisis and can’t relocate or even just get outside for an extended period of cleansing fresh air.

Though you often can’t see or smell mold, the presence of it in your home can be problematic to your health. For those with chronic Lyme disease, undetected mold can exacerbate existing health problems. On one end of the spectrum, symptoms associated with mold exposure may be mild, such as itchy eyes or sneezing that comes with an allergic reaction. But on the other end, exposure to mold, especially toxic mold, can lead to a host of life-altering symptoms.

While the connection between Lyme disease and mold illness is not yet fully understood, one thing is clear: Mold exposure can hinder your recovery from chronic Lyme disease and coinfections. Since reducing mold exposure is of interest to most Lyme patients, let’s review some basic facts about this topic.

Mold Basics

1. Mold is Everywhere.

Mold is a type of fungus that reproduces via spores that float in the air. Mold spores are normally present in the environment and 50% of American homes. In all likelihood, you can probably find evidence of mold in every home if you look for it. For some people, even slight exposure to mold can be problematic, especially when it’s coupled with immune dysfunction that’s so common in people with chronic illnesses.

2. Mold Needs Certain Conditions to Thrive.

Three conditions are needed for mold growth: an ideal temperature, a food source, and moisture. As luck would have it, the temperature in most homes is suitable for mold growth, and cellulose-rich building materials such as drywall, wood studs, ceiling panels, and wet insulation provide an excellent food source, according to a paper in the International Journal of Construction Education and Research. Dirt and dust can act as a food source for mold, too. It can also grow inside wallpaper and ventilation ducts, behind walls, above ceilings, and underneath carpets and floorboards.

Black and orange vacuum cleaner standing on fluffy carpet in the living room before or after the cleaning. Home, housekeeping concept.

Keep in mind that the potential for a problem exists in any indoor environment damaged by water intrusion from conditions such as rising damp from basements, plumbing leaks, inadequate ventilation, or seepage of rain due to a leaky roof or windows. Humidity of 60% or higher is sufficient moisture to promote mold growth, according to the United States Environmental Protection Agency (EPA).

3. Everyone Responds Differently to Mold.

While some may not notice it all, those who are allergic will have a sensitive immune response that alerts them to the fact that they need to leave the moldy environment. Symptoms of an allergic response include:

  • Coughing
  • Sneezing
  • Eye irritation
  • Congestion
  • Postnasal drip
  • Dry, scaly, or itchy skin

Some people, however, won’t display the signs and symptoms of an allergic reaction. They may not recognize that mold is present, and instead, unknowingly inhale mold spores. These spores can attach to the mucous membranes of the sinuses, lungs, and gastrointestinal system, where they can grow.

Sick african american girl working from home office. Ill young black woman with cold, sitting at desk with laptop computer and sneezing for allergy.

However, for individuals who have the HLA-DR gene, which is present in approximately 25% of the population, they are more likely to experience adverse symptoms when they come in contact with mold and mold mycotoxins than other people. The reason? The HLA-DR gene prevents people from developing the antibodies needed to remove mycotoxins, the toxic substances produced by mold that can make a person sick. A laboratory blood test can be ordered by your physician or another qualified healthcare professional to determine if you carry this gene.

Despite valiant efforts to resolve Lyme disease and coinfections, some patients might find that their health continues to plummet — and undetected mold in their home could be the culprit. Prolonged exposure to mold and mycotoxins can cause a plethora of symptoms, including:

Ultimately, mold toxins in your home can impair your immune system and lead to a general decline in health. Take note of whether you feel poorly while inside your home and better when you’re outside. If that’s true for you, it could be a clue that mold is a problem inside your house.

You Suspect Mold in Your Home. Now What?

Though the thought of mold in your house is overwhelming, try not to panic. It’s a common problem, and it can be mitigated with the right actions. Here are some steps you can take.

Consider a Self-Administered Mold Test.

There are several screening tests available that can be performed without the need to call in a professional. The benefit of self-testing is that it gives you a visual scale of the types and quantities of mold that are in your home, helping you gauge whether you can handle the cleanup yourself or if you need a professional. One such test is the Environmental Relative Moldiness Index, or ERMI, available through specialty labs like Mycometrics or Envirobiomics. The ERMI contains information on 36 different mold species that can occur in a home environment, which helps to calculate the total mold burden to which you’re exposed.

To use a test kit, you’ll need to take dust samples from your home, which will be evaluated using DNA-analysis. The test generates an index value used for comparison to other homes in the United States. Depending on the testing company, costs range from $240 to $300.

Desk at laboratory with test tubes, scientist with gloves on.

Another screening test to consider is the Environmental Mold & Mycotoxin Assessment (EMMA) test by RealTime Laboratories. A small sample of dust or material from your air conditioner or heat filters is required. The EMMA test uses a quantitative polymerase chain reaction (PCR) procedure to determine the presence and relative abundance of 10 of the most toxigenic molds and 15 of the most poisonous mycotoxins. The test costs approximately $400.

Determine Who Should Do the Cleanup.

If you have visible water damage or an active leak, you might not know what to do to effectively mitigate mold growth in your home. Is it safe to handle water-damaged areas of your home on your own, or do you need help from a professional? The answer depends both on the magnitude of the problem, and the state of your health.

According to the EPA, if the moldy area is less than about 10 square feet, individuals without health concerns may be able to complete the job following their guidelines. They caution, however, that the problem will likely recur if the water issue is not fixed. (For safe removal of mold, refer to the EPA’s mold cleanup guidelines.)

Spray bottle and sponge near black mould wall. House cleaning concept

Some of the precautions that should be taken by healthy individuals during cleanup to limit exposure to mold and mold spores include using:

  • A N-95 respirator (normally available at most hardware stores, they are in short supply now; it’s best to postpone mold cleanup until one can be obtained)
  • Gloves
  • Goggles

But if you’re an individual with health concerns, the EPA recommends consulting a health professional before starting cleanup. Additionally, if the problem exists in an area that is greater than 10 square feet, or in cases when mold is suspected but not visible, it’s also best to bring in a professional.

Use These Tips for Working with a Professional.

Although mold remediation can be an expensive endeavor, proper steps to eliminate unwanted mold and moisture can, in some instances, vastly improve your health by reducing your exposure to harmful and inflammatory mycotoxins. When working with a professional for mold cleanup or remediation, keep the following in mind:

  • Consider using an inspector that does not perform remediation to prevent a possible conflict of interest.
  • Review your state guidelines; some states may have specific regulations regarding licensing and remediation.
  • To locate a mold-certified investigator, consultant, or contractor for assessment or remediation, visit the American Council for Accredited Certification. Residents of the United States can search for certificants by zip code.
  • Another useful website is that of the International Society for Environmentally Acquired Illness (ISEAI). This site provides a list of ISEAI indoor environmental professionals (IEPs) who perform onsite assessments of residential and commercial properties, oversee remediation efforts, and provide advice about maintaining a healthy home or work environment. If desired, they can work closely with ISEAI medical professionals (who are also listed on the site) to help connect the dots between environmental exposures and health issues.
  • Request that the contractor follows the recommendations of professional or governmental organizations, such as the EPA or the American Conference of Governmental Industrial Hygienists (ACGIH).

But What If You Rent?

If you’re a tenant and you find yourself in a moldy environment, the situation may be more complicated to deal with — but it’s not impossible. The following is for general information purposes only and does not constitute legal advice.

1. Educate Yourself.

Learning about your landlord’s responsibilities regarding mold may be helpful in navigating toward a solution, so be prepared to do a little research. To date, there are no federal laws that set acceptable exposure limits or building tolerance standards for mold in residential buildings. Only a few states (California, Indiana, Maryland, New Jersey, and Texas) and a few cities (New York City and San Francisco) have taken steps to address safe mold levels.

If you would like to learn more about the mold rules and regulations in your area, the following sources of information can be useful to you:

  • Check with your state department’s environmental protection agency (for example: State of Illinois Environmental Protection Agency) or your state department of public health.
  • Contact your city manager, mayor’s office, or the local health department to determine if there are any local mold-related rules (such as health and safety codes) that might apply to your situation.
  • Your local tenant’s council or housing authority may also be able to provide useful advice or advocate on your behalf.

Even if there are no laws applicable to mold in your city or state, the landlord may still be liable for a mold problem in your rental property due to an implied warranty of habitability. Simply put, this means that the landlord has the responsibility to provide a safe and livable rental home. This includes certain necessary features and the absence of significant dangers, one of which may be mold.

Apartment Remodeling Job. Caucasian Worker in His 30s Patching Drywall in the Remodeled Bathroom

However, some landlords may be less than enthusiastic about making repairs where mold is concerned. Landlord/tenant laws vary by state, and the terms of the warranty can sometimes be controversial.

So, before you take any action such as withholding rent, deducting the cost of repairs from your rent, or breaking the lease, be sure to consult with a lawyer, a local tenant’s council, or the housing authority to avoid legal and financial consequences resulting from failure to comply with the law.

2. Create A Paper Trail.

Start by sending a dated and signed letter to notify your landlord of the problem. Make a request for remediation, but be advised that some landlords may be reluctant to pay for it. If you need to pursue legal options, it may be important to create a paper trail by doing the following:

  • Communicate with the landlord or property manager in writing, when possible.
  • Sign and date all correspondence, and keep copies for your records.
  • Keep a log of any verbal communications, including the date, time, and the name of the person with whom you spoke.
  • Be sure to document the presence of mold in your dwelling and on your possessions as best you can.
  • Take pictures of any visible mold, and keep copies of the results of any inspection and testing.

Documenting that you have been diagnosed with Lyme disease or that you have the HLA-DR gene might also be helpful by showing that you are more likely to be susceptible to mold-related illness. Your landlord may be more inclined to make the necessary changes or let you out of your lease without charging you a fee.

If you have health issues you believe are related to mold exposure, keep a file of relevant medical records and bills. If you have a significant health impairment caused by mold, you might want to seek the advice of an attorney to see what legal course of action is available to you.

Additionally, contact your renter’s insurance agent if your possessions have been damaged by mold. Depending on your coverage, your policy may cover the loss.

3. Act Responsibly.

Ultimately, it’s important to understand that tenants have a responsibility to prevent mold in a rental property, too. The landlord is not liable when the tenant’s negligence is the sole cause of water damage or mold growth.

Simple steps, such as running the bathroom fan when showering and using the exhaust fan when cooking, can reduce humidity in the home. Using ceiling fans, air conditioners, and dehumidifiers will also help. Consider purchasing a humidity meter (they generally cost $10-$50) to monitor relative humidity, which should ideally be kept between 30% and 50%.

To have the best chance of preventing mold growth if water damage arises, resolve all water problems and dry areas and items affected by water intrusion within 24-48 hours. Notify your landlord of water-related issues immediately.

Above all, be vigilant with respect to preventing, identifying, and remediating mold issues. Your health may depend on it.

Dr. Rawls is a physician who overcame Lyme disease through natural herbal therapy. You can learn more about Lyme disease in Dr. Rawls’ new best selling book, Unlocking Lyme.
You can also learn about Dr. Rawls’ personal journey in overcoming Lyme disease and fibromyalgia in his popular blog post, My Chronic Lyme Journey.


1. A Brief Guide to Mold, Moisture, and Your Home. United States Environmental Protection Agency website.
2. Arumala JO. Mold and the construction industry. International Journal of Construction Education and Research. 2006; 2(2): 75-89. doi: 10.1080/15578770600775868
3. Implied Warranty of Habitability. Cornell Law School Legal Information Institute website.
4. Mold Course Chapter 2: Why and Where Mold Grows. United States Environmental Protection Agency website.
5. Nathan N. Toxic: Heal Your Body from Mold Toxicity, Lyme Disease, Multiple Chemical Sensitivities, and Chronic Environmental Illness. Las Vegas, NV: Victory Belt Publishing Inc; 2018.
6. Strasheim C. New Paradigms in Lyme Disease Treatment: 10 Top Doctors Reveal Healing Strategies That Work. South Lake Tahoe, CA: Biomed Publishing Group; 2016.
7. Tuuminen T, Rinne KS. Severe Sequelae to Mold-Related Illness as Demonstrated in Two Finnish Cohorts. Frontiers in Immunology. 2017 Apr 3; 8: 382. doi: 10.3389/fimmu.2017.00382