Remediating mold damage after flooding mitigates risks for respiratory health
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Key takeaways:
- Most mold spores are airborne, and they can impact respiratory health.
- Bleach and other irritants can make asthma worse.
- Remediation should focus on reducing moisture and humidity.
ANAHEIM, Calif. — Patients with asthma can remediate mold damage in their homes after flooding caused by natural disasters, according to a presentation at the American College of Allergy, Asthma & Immunology Annual Scientific Meeting.
“This study was done mostly because in New Orleans, there are a lot of hurricanes and floods,” Amber Hardeman, MD, MPH, MBA, pediatrics chief resident at Tulane University School of Medicine, told Healio. “And with global warming, there is a lot more of that occurring.”
As flooding creates damp indoor environments, Hardeman and her colleagues explained, mold starts to grow on any surface and penetrates the air as well.
“Most people think that they can see the mold. That’s the only time that it’s there,” Hardeman said. “But the majority of mold spores are in the air.”
Patients with respiratory conditions, allergies and immunosuppression are most susceptible to the effects of this exposure.
“So, they have these severe exacerbations,” Hardeman said.
Hardeman and her colleagues conducted a scoping review of 20 peer-reviewed articles in addition to guidelines from organizations such as CDC, Environmental Protection Agency, Occupational Safety and Health Administration and American Academy of Allergy, Asthma & Immunology.
“Our primary objective was to figure out how does mold affect the public after natural disasters, storms and flooding, and what is the safest way for patients to mitigate harmful effects after the mold is cleared,” she said.
The impacts of mold
The review yielded four validated mechanisms for mold’s direct adverse outcomes on health, including hypersensitivity, toxicity, infection and irritation.
Hypersensitivities include allergic rhinitis, allergic asthma, nonallergic asthma, allergic bronchopulmonary aspergillosis and mycosis, allergic fungal sinusitis and hypersensitivity pneumonitis.
Also, patients with asthma are 2.16 times more likely to die when mold counts exceed 1,000 spores/m3, the researchers found.
Further, volatile organic compounds (VOCs) — which are carbon-containing compounds of low molecular mass that evaporate at normal temperatures and pressures — from growing molds irritate airways as well.
In fact, one study the researchers reviewed indicated that the incidence of invasive mold infections increased from 2.5 before hurricanes to 3.69 after hurricanes, although another study found no such increase.
“It sometimes is a little difficult to tell what the treatment course was afterwards,” Hardeman said. “That’s something that we’re looking into moving forward.”
Mold has socioeconomic impacts as well, the authors discovered.
“One of the biggest things we also noticed was that there is a very large, disproportionate amount of African American and Hispanic underserved populations that have these mold exposures because the neighborhoods that they tend to live in have a higher incidence of poverty,” Hardeman said.
The authors said that these neighborhoods have poor housing infrastructure and unequal health care access and quality in addition to mold.
Additionally, the authors called anxiety about mold common and said that unsubstantiated effects such as fatigue and rashes often are blamed on mold exposure.
Remediation methods
The review did not produce any specific guidelines for remediation from a physician’s standpoint, Hardeman said, but industry and government groups provided recommendations. These recommendations included four different strategies based on the size of the infested area.
Level 1 infestations measuring less than 10 square feet would require N95 masks while water and detergent are used to scrub mold from nonporous surfaces. Residents do not need to be displaced.
With Level 2 infestations, measuring between 10 square feet and 30 square feet, people who are removing the mold should use dust suppression materials and dispose of the damaged materials. Biocides and chemicals such as chlorine bleach are not recommended.
“It’s actually more damaging than helpful for people to use harmful bleaches and things that they’re often told to use because those are irritants in themselves, which give you worse symptoms for your asthma,” Hardeman said.
Measuring between 30 square feet and 100 square feet, Level 3 infestations should involve remediation professionals. Structures should be covered and/or removed, and ventilation ducts and vents should be sealed. Also, these areas should be unoccupied except by the remediation workers, who would use HEPA vacuums and damp cloths or detergent solutions for cleaning.
Similarly, professionals should address Level 4 infestations, which measure 100 contiguous square feet or more. These structures may need to be completely removed, and areas should be dried with less than 60% humidity in the remaining structure.
The authors cautioned that remediation work can generate particulate matter that is more harmful than the mold and emphasized the importance of protective equipment.
Additionally, the authors said that excessive testing and/or remediation driven by fear is costly and fails to address underlying fears.
“It’s not necessarily indicated to sample the mold, because depending on where you sample, you’ll get different values,” Hardeman said.
Residents should presume that homes that have been damaged by flooding still have mold unless the moisture has been removed, the authors said.
“The most important thing is to dry out the space or to cleanse the air with HEPA filters,” Hardeman said.
Large wet porous material such as furniture, carpeting and insulation should be removed to aid in drying out the home. Small porous materials such as blankets and toys can be washed and dried. Materials that are not porous such as tables and floors can be cleaned with water or vinegar solution instead of caustic products.
If the home’s HVAC system is operational, it should be used in the drying process, along with industrial dehumidifiers if they are available, the authors also recommended. Efforts at drying the home should continue until humidity falls below 60%.
Patients with hypersensitivities and other chronic medical conditions should not participate in the remediation, the authors continued.
Public health
The authors called for public health messages that address the harms caused by fear of mold as well as the harms caused by mold itself after flood.
Also, the authors called for public health initiatives that address structural housing inequalities and cleanup efforts after flooding to mitigate risks due to prolonged exposure to mold among residents at high risk for exacerbations.
Resources are available to help people with these remediation efforts too, Hardeman said.
“We’re primarily focusing on education and helping them to understand who can help them remediate the mold in their houses,” Hardeman said.
Community groups can step in to help clean and dry out flooded homes, especially homes of the elderly or children with asthma, she continued.
Keeping people out of homes and neighborhoods with significant damage is difficult, Hardeman said.
“Even if their specific home wasn’t hit as bad, when they’re going through the neighborhood, they’re still exposed to all of the spores that are in the environment,” she said. “They’re still worsening their health care status.”
Yet finding alternatives for these residents is challenging, Hardeman said, which often means staying with relatives or friends outside the area or in public shelters.
“But in areas like New Orleans, a lot of times, that’s not possible,” she said.
Despite these challenges, Hardeman said, these efforts are important because approximately 20% of the world’s population has asthma, making this impact especially important for allergists and immunologists.
“And that number is growing,” she said.