science in ACTION

BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS

SEPA

www.epa.gov/ord

HUMAN HEALTH
RESEARCH PROGRAM
www.epa.gov/ord

RESEARCH SHOWS THE ROLE OF

MOLD IN CAUSING OR EXACERBATING ASTHMA

Issue:

The number of Americans diagnosed
with asthma, particularly children,
has reached epidemic proportions. To
improve understanding of the human
health implications of asthma, the
U.S. Environmental Protection Agen-
cy's Office of Research and Develop-
ment has developed a targeted asthma
research program.

One area of asthma research involves
the potential role that mold plays in the
development or exacerbation of asthma.
Recently, there has been much media
attention devoted to Stachybotrys char-
tarutn, a type of black mold or fungus
that has been associated with a range of
health problems including asthma.

Science Objective:

Few hypotheses about mold exposure,
its influence on asthma, or methods for
prevention have been tested scientifi-
cally. As a result, EPA has made mold,
or fungal bioaerosols, a major focus of
its asthma research program.

Researchers are currently working
to identify and describe the many
different molds commonly present in
household environments. They hope
to determine which molds pose the

greatest risks and whether any has the
capacity to cause asthma.

Scientists also intend to determine
how much mold a person must inhale
to cause an effect. Inhaling just a few
particles may sensitize people s lungs,
making them more likely to react to
future exposure. In addition, genetic
variations in humans may cause cells to
respond differently which may explain
why mold and other allergens cause
or exacerbate asthma in some people
but not in others. EPA researchers are
working to determine the specific ways
in which cells and organs respond
to molds and other environmental
pollutants.

Application and Impact:

In one study, scientists exposed mice
to samples of Stachybotrys taken from
homes and looked for immune system
responses typical of allergies as well as
inflammation and functional changes in
the animals* lungs. The results showed
that the mold can indeed cause a disease
similar to asthma in mice. Meanwhile,
other EPA scientists have developed
sophisticated procedures for identifying
Stachybotrys and other molds in indoor
environments, making it possible to
determine which molds are present in

a given household. These procedures
include methods for rapidly measuring
the amounts of different fungi present
in dust and measuring a biomarker that,
when found in a person's blood, indi-
cates exposure to Stachybotrys. These
studies set the stage for further research
that will help determine if humans are
responding to the same allergens as
mice and whether these responses can
be associated with asthma.

EPA investigators have also been evalu-
ating strategies for preventing mold
growth. Strategies include applying
antifungal sealants for fiberglass and
galvanized steel used in heating and
air conditioning systems. Studies show
that sealants can reduce mold growth on
fiberglass and can completely prevent
growth on galvanized steel.

REFERENCES:

U.S. Environmental Protection Agency, Office of
Research and Development, Asthma Research Results
Highlights, EPA Report, EPA 600/R-04/161, 2005,
Washington, D.C.

U.S. Environmental Protection Agency, Office of
Research and Development, Asthma Research Strategy,
EPA Report, EPA 600/R-01/061, 2002, Washington, D.C.

CONTACT:

Hillel Koren, Ph.D., Environmental Protection Agency's
Office of Research and Development, 919-966-9791,
Koren.hillel @ epa.gov

U.S. Environmental Protection Agency

Office of Research and Development

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