Date: May 25, 2004
FOR IMMEDIATE RELEASE
Indoor Mold, Building Dampness Linked
to Respiratory Problems and Require Better Prevention
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.
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. Excessive indoor
dampness is a widespread problem that warrants action at the
local, State, and National levels."
Excessive dampness influences whether mold as well as
bacteria, dust mites, and other such agents are present and
thrive indoors. Moreover, wetness may cause chemicals and
particles to be released from building materials. Many
studies of health effects possibly related to indoor
dampness do not distinguish the specific health effects of
different biological or chemical agents.
Through its careful review of the available scientific
studies, the committee found sufficient evidence to conclude
that mold and damp conditions are associated with asthma
symptoms in asthmatics who are sensitive to mold, and to
coughing, wheezing, and upper respiratory tract symptoms in
otherwise healthy people. An uncommon ailment known as
hypersensitivity pneumonitis also is associated with indoor
mold exposure in genetically susceptible people. Damp
conditions and all they entail 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."
Studies on animals and cell cultures in labs have found
toxic effects from various microbial agents, raising
concerns about whether these same agents growing in
buildings can cause illness in people. Molds that are
capable of producing toxins do grow indoors, and toxic and
inflammatory effects also can be caused by bacteria that
flourish in damp conditions, the report noted. Little
information exists on the toxic potential of chemicals or
particles that may be released when building materials,
furniture, and other items degrade because of wetness. The
committee recommended that current animal studies of
short-term, high-level inhalation exposures to microbial
toxins be supplemented with new research that evaluates the
effects of long-term exposures at lower concentrations.
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, building contractors, facility
managers, and maintenance staff do not always apply this
knowledge, the report says.
The committee had insufficient information to recommend
either an appropriate level of dampness reduction, or a safe
level of exposure to organisms and chemicals linked to
dampness. Better standardized methods for assessing human
exposure to these agents are greatly needed, the report
says. It calls for studies that compare various ways to
limit moisture or eliminate mold and to evaluate whether the
interventions improve occupants' health.
The study was sponsored by the Centers for Disease Control
and Prevention. The Institute of Medicine is a private,
nonprofit institution that provides health policy advice
under a congressional charter granted to the National
Academy of Sciences. A committee roster follows.
INSTITUTE OF MEDICINE
Board on Health Promotion and Disease Prevention |
