WASHINGTON - Scientific evidence links mold and other factors related to damp conditions in homes and buildings to asthma symptoms in some people with the chronic disorder, as well as to coughing, wheezing, and upper respiratory tract symptoms in otherwise healthy people, according to a new report from the Institute of Medicine of the National Academies.

However, the available evidence does not support an association between either indoor mold or dampness and the wide range of other health complaints that have been ascribed to them, the report says. Given the frequent occurrence of moisture problems in buildings and their links to respiratory problems, excessive indoor dampness should be addressed through a broad range of public health initiatives and changes in how buildings are designed, constructed, and maintained, notes the committee that wrote the report.

"An exhaustive review of the scientific literature made it clear to us that it can be very hard to tease apart the health effects of exposure to mold from all the other factors that may be influencing health in the typical indoor environment," said committee chair Noreen Clark, dean, School of Public Health, University of Michigan, Ann Arbor. "That said, we were able to find sufficient evidence that certain respiratory problems, including symptoms in asthmatics who are sensitive to mold, are associated with exposure to mold and damp conditions. Even though the available evidence does not link mold or other factors associated with building moisture to all the serious health problems that some attribute to them, excessive indoor dampness is a widespread problem that warrants action at the local, state, and national levels."

According to the committee, an uncommon ailment known as hypersensitivity pneumonitis also is associated with indoor mold exposure in genetically susceptible people. Damp conditions may be associated with the onset of asthma, as well as shortness of breath and lower respiratory illness in otherwise healthy children, although the evidence is less certain in these circumstances. Likewise, the presence of visible mold indoors may be linked to lower respiratory tract illness in children, but the evidence is not as strong in this case.

The committee found very few studies that have examined whether mold or other factors associated with indoor dampness are linked to fatigue, neuropsychiatric disorders, or other health problems that some people have attributed to fungal infestations of buildings. The little evidence that is available does not support an association, but because of the dearth of well-conducted studies and reliable data, the committee could not rule out the possibility.

Moisture and mold problems stem from building designs, construction and maintenance practices, and building materials in which wetness lingers. Technical information describing how to control dampness already exists, but architects, engineers, contractors, facility managers, and maintenance staff do not always apply this knowledge, the report says. Training curricula on why dampness problems occur and how to prevent them should be produced and disseminated, says the committee.

Guidelines for preventing indoor dampness also should be developed at the national level to promote widespread adoption and to avoid the potential for conflicting advice from different quarters, the committee notes. In addition, building codes and regulations should be reviewed and modified as necessary to reduce moisture problems.

Publication date: 06/07/2004