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, says a new report from the Institute of Medicine of the National Academies. However, the available evidence does not support an association between either indoor dampness or mold 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, said 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."

This report is the result of a request by the Centers for Disease Control and Prevention for a comprehensive review of the scientific data on the relationship between damp or moldy indoor environments and adverse health effects. In essence, our purpose was to provide a science-based, objective answer to the questions of whether mold growing in damp building spaces can cause health problems, and -- more broadly -- whether all the many factors that are related to indoor dampness can lead to illness.

The committee and its consultants took a broad- based approach to this charge. We examined studies that addressed why indoor moisture problems develop and how dampness influences mold and bacterial growth. We also examined studies on how moisture affects building materials and furnishings. We reviewed the laboratory, clinical, and epidemiologic studies on how damp indoor environments influence the health of occupants. We also looked at research on strategies for preventing dampness and cleaning contaminated spaces. Finally, we offered our perspectives on an appropriate public health response to damp indoor environments.