Flood Damage 101

The following guidance is intended for the general public and households with diagnosed or probable Environmentally Acquired Illness (EAI).

Written by ISEAI’s Indoor Environmental Professional Committee | Image credit: FEMA Photo Library, photograph by Bruce Kinney

What do flood-affected people need to know about mold and water damage?

In the initial days after major flooding, most people are focused on emergency needs, evacuating family members, animals, and securing safety. Understandably, this means that immediate response to floodwater damage and mold is often delayed.

Unfortunately, floodwater commonly contains dangerous contaminants such as sewage, bacteria, gasoline, agricultural runoff, and more. As the water recedes, these contaminants are left behind and can soak into porous materials like wood, drywall, insulation, and personal belongings. For this reason, most porous materials that were in direct contact with floodwater should be discarded.

In addition to contamination, floodwater causes significant water damage that creates ideal conditions for mold and other microbial growth. Mold inside buildings can negatively impact health and, in some people, lead to debilitating illness.

The U.S. Environmental Protection Agency (EPA) states:

“Flood water can make the air in your home unhealthy. This is because when things remain wet for more than two days, they usually get moldy. Inhaling mold can cause adverse health effects, including allergic reactions. Mold also can damage materials in your home. In addition, flood water may contain microorganisms, such as bacteria, or chemicals which may affect your health.”

—U.S. EPA, Resources for Flood Cleanup and Indoor Air Quality

Take Floodwater Damage and Mold Seriously

After a major flood, people are often in survival mode, focused on how to return to their homes and restore some sense of normalcy. Because of this urgency, it’s common to hear well-meaning advice from neighbors, family members, public officials, contractors, or insurance adjusters suggesting that discarding all flood-damaged porous materials and belongings either is or isn’t realistic or necessary.

However, it’s important to understand: Even if others around you are not taking these steps, floodwater damage and mold exposure should be taken seriously.

Some items are almost always restorable using environmental cleaning steps, such as smooth plastic, glass, ceramic, and non-corroded metal objects. However, items that have absorbed water, including books, papers, carpeting, and wood furnishings that have warped, swollen, or cracked, are usually not salvageable. While particularly valuable or sentimental items may be restorable through specialized and often expensive restoration services, these efforts are not always cost-effective.

This is where tough decisions need to be made, but qualified professional guidance can help. An experienced team can help assess what can be saved and what poses a risk to health or reinfestation.

Flood cleanup and safe re-occupancy are not just about what’s practical; they’re about protecting your long-term health and well-being.

Considerations in Do-It-Yourself Flood Cleanup

In the aftermath of a flood, many people end up doing some or all of the cleanup themselves—often with help from friends, family, or volunteers—without access to trained professionals or specialized equipment. This typically happens due to financial limitations, lack of flood insurance, delays in federal or state assistance, or shortages of qualified contractors and materials in hard-hit areas.

If you undertake your own cleanup, it’s important to recognize that flood cleanup often involves exposure to contaminated materials that can pose serious health risks. Take appropriate precautions: Always use personal protective equipment (PPE), including particle respirators, gloves, and protective clothing.

Mold and microbial contamination are especially concerning. The U.S. Environmental Protection Agency advises:

“Protect yourself and loved ones against hazards. People with breathing problems, like asthma, or who have weakened immune systems should stay away from moldy sites. Children should not take part in disaster cleanup work.”

— U.S. EPA, Homeowners’ and Renters’ Guide to Mold Cleanup After Disasters

While it may be tempting to rush through cleanup to regain access to your home, prioritizing health and safety is essential. Whenever possible, consult with experienced professionals to guide or support your efforts.

When Mold Exposure Leads to Chronic Illness

At ISEAI, our member physicians and Indoor Environmental Professionals (IEPs) specialize in supporting individuals who are highly sensitive and living with complex, chronic illness. These patients may react severely to a wide range of environmental exposures—including mold—resulting in what is known as environmentally acquired illness (EAI).

Some people are more vulnerable to environmental triggers than others. Just as some individuals react strongly to pollen, or peanuts, or common viruses while others remain unaffected, mold exposure can have dramatically different effects from person to person.

For those who are susceptible, even low levels of indoor mold can lead to serious, long-lasting health effects.

Understanding and addressing these sensitivities is critical to improving quality of life—and often requires the collaboration of both medical and environmental professionals who recognize and treat EAI.

Will I Be Affected in This Way?

It’s difficult to predict who will develop more severe symptoms or long-term illness from mold exposure. Some individuals are highly susceptible, while others may show little or no symptoms—even when living in the same environment.

ISEAI physicians often see patients who were unknowingly affected by mold in their homes, sometimes for months or years before recognizing the connection to their symptoms.

To reduce risk, follow the U.S. Environmental Protection Agency’s guidance: Avoid exposure to elevated mold levels. This needs to be done both during the cleanup phase and as part of long-term protection of your home and belongings.

Whenever possible, flood cleanup and remediation should be performed by qualified professionals who follow industry best practices. This includes using engineering controls such as containment barriers to limit cross-contamination when removing flood-damaged or mold-contaminated materials.

Before beginning remediation or reconstruction, consider having a qualified Indoor Environmental Professional (IEP) assess the damage. If you are already aware that you are mold-sensitive, seek out an IEP who is experienced in working with individuals affected by environmental illness.

Note: Drying out the building should not be delayed—it is one of the most urgent first steps.

Watch for Future Signs of Mold Problems

Once your home is fully dried and all flood-damaged or mold-contaminated porous materials have been properly removed, it’s important to stay alert for signs that mold or microbial issues may still be present—or may return due to lingering moisture or humidity.

Be on the lookout for warning signs such as:

• Visible mold growth inside your home
• Water-damaged materials or belongings that were never discarded
• Consistently high indoor humidity (above 50%)
• Musty or earthy odors—especially in previously flooded areas

If you observe any of these signs, consider contacting an Indoor Environmental Professional (IEP) for a thorough evaluation of your home’s indoor air quality.

For guidance on how to find a qualified IEP, visit: www.iseai.org/find-a-professional

In addition to what you see and smell, pay attention to how you feel. These experiences may suggest a continuing environmental problem:

• You feel worse ever since the flooding
• You feel noticeably better when spending extended time outdoors
• You feel better in other locations (such as while on vacation or at a relative’s home)
• You feel better in certain parts of your home than in others (e.g., upstairs vs. basement)

These patterns could indicate that mold or other environmental conditions in your home are affecting your health.

What Symptoms Should I Be Looking Out For?

Mold exposure can cause a wide range of symptoms that may affect multiple systems in the body. People often describe fatigue, muscle aches or cramps, joint pain, skin pain or sensitivity, headaches (including sharp, stabbing “ice pick” pain), brain fog or difficulty concentrating, light sensitivity, abdominal pain, digestive issues such as diarrhea or constipation, frequent urination or increased thirst, poor sleep or non-restorative rest, mood changes, irritability, anxiety, depression that does not improve with treatment, and intrusive negative thoughts or rumination.

If you were affected by flooding and are experiencing any of these symptoms—or recognize the warning signs mentioned earlier—it’s a good idea to consult a physician trained in environmentally acquired illness and mold-related health concerns. You can start your search at: www.iseai.org/find-a-professional

A qualified physician will evaluate your medical history, signs and symptoms, and may recommend lab testing to help rule out various causes of your symptoms through a process called differential diagnosis. Although mold exposure should always be taken seriously, it is important to understand that there are many possible causes of symptoms like these—including infections, autoimmune or neurodegenerative conditions, mold exposure, and more. Identifying the correct diagnosis and uncovering underlying root causes is essential to getting appropriate treatment and improving long-term health.

Moving Forward Safely

Drying, remediating, and rebuilding after a flood is a major undertaking—but with the right support, it is possible. Don’t try to take it all on alone. Whenever you can, seek qualified guidance to help assess damage, make cleanup plans, and support safe re-occupancy.

If local resources are limited, many Indoor Environmental Professionals (IEPs) are available for virtual consultations. These experts can help you create a customized plan to evaluate, clean, and remediate your property—step by step.

Being displaced from your home is extremely challenging, especially when recovery takes weeks or months. Even so, it’s vital to prioritize your family’s health and well-being—both during the initial response and throughout the rebuilding process.

Reducing exposure to flood-related contaminants and mold is key to supporting long-term recovery. Medically-sound professional environmental guidance can make all the difference.

Downloadable PDF of this content: Flood Damage 101

More mold resources: iseai.org/resources

Disclaimer: This is an educational publication from ISEAI non-profit, created by the ISEAI Indoor Environmental Professional Committee, a group of experienced indoor environmental professionals (IEPs) who specialize in supporting people who are medically affected by environmental exposures. This does not replace individualized professional advice. Please consult your own licensed medical and qualified environmental professionals for advice most appropriate to your unique circumstances.

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