Background
Mold is a type of fungus that requires water or moisture to grow. Mold contamination inside buildings can be caused by problems such as water leakage through roofs or walls, plumbing leaks, uncontrolled humidity, or condensation. Mold contamination and dampness are common in buildings in the U.S. With the expected increase in heavy precipitation events resulting from climate change, these problems may become even more prevalent in many areas.
Exposure to indoor mold and dampness can cause a variety of adverse health effects. According to the California Department of Public Health (CDPH), “Human health studies have led to a consensus among scientists and medical experts that the presence in buildings of (a) visible water damage, (b) damp materials, (c) visible mold, or (d) mold odor indicates an increased risk of respiratory disease for occupants. Known health risks include: the development of asthma; the triggering of asthma attacks; and increased respiratory infections, allergic rhinitis, wheeze, cough, difficulty breathing, and other symptoms.”
The U.S. EPA notes that allergic reactions to mold are common and can occur in people who are already mold-allergic and in those who are not allergic. As the CDPH underscores, "If you can see mold, water damage, or moisture, or smell mold, there is at least some increased health risk. The more extensive or severe the dampness and mold, the greater the risk of health effects.”
ELI Indoor Mold Materials
Database of State Indoor Air Quality Laws (Mold Excerpt)
Topics in School Environmental Health - Overview of State Laws: Mold
Indoor Air Quality in Rental Dwellings: ELI Policy Brief
Indoor Air Quality in Homes: State Policies for Improving Health Now and Addressing Future Risks in a Changing Climate (Mold Chapter) (2016)
Reducing Environmental Exposures in Child Care Facilities: A Review of State Policy (Mold Chapter) (2015)
ELI research reports highlight policies in effect at the time of publication. Other materials have been updated periodically to reflect new developments.
Opportunities for Policy Action
Controlling moisture is the key to controlling indoor mold growth. To reduce exposure to mold and dampness indoors it is important to act quickly to fix water problems or leaks, clean or remove moldy materials, and dry or throw out damp materials. EPA provides guidance on steps for cleaning up mold and notes that “in most cases, if visible mold growth is present, sampling is unnecessary.”
State policy can play an important role in advancing evidence-based practices to prevent and correct indoor mold and dampness problems in homes, schools, workplaces, and other buildings. Building codes and related policies governing new construction and renovations can incorporate moisture control measures. State laws that set minimum property maintenance standards for existing rental dwellings, schools, child care facilities, and workplaces can require building owners and managers to conduct preventive maintenance and take prompt corrective action. It is also important for states to ensure that agencies have adequate resources for implementing mold-related laws and providing technical assistance to building owners and operators.
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