Common house dust may be an important source
of a potentially dangerous class of chemicals called polybrominated
diphenyl ethers (PBDEs), according to an exploratory study
by researchers at the National Institute of Standards and
Technology (NIST) and the Environmental Protection Agency
(EPA). Recent studies by others have found that PBDE concentrations
are increasing rapidly both in the environment and in human
blood, fat tissue and breast milk.
PBDEs have been used widely in consumer products for years
because they are effective flame retardants, greatly increasing
the fire safety of products ranging from carpeting and cushions
to televisions, computers and coffee makers. Toxicological
data on PBDEs are still limited, but the compounds have been
implicated in developmental, reproductive, neurotoxicity and
thyroid effects in rats, mice and fish, and may be carcinogenic.
Researchers in Europe and the United States found concentrations
of PBDEs higher in Americans than in Europeans, although it
is not known if these levels affect human health.
While some PBDE exposure may accumulate through diet, the
new study found that house dust and the home environment are
likely additional sources.
The NIST/EPA survey of 17 homes in the Washington, D.C.,
and Charleston, S.C., areas found high concentrations of PBDEs
in household dust, ranging from 700 to 30,100 nanograms per
gram. Researchers analyzed both dust from floors and clothes
dryer lint for 22 variants of commercial PBDEs and found PBDEs
in every sample.
Although the new study is limited, say researchers, it highlights
the need to study house dust as the primary source of PBDE
exposure. In particular, the authors note that small children
are more at risk than adults to dust exposures since they
are more prone to putting dusty hands and toys in their mouths.
For further information, see https://www.nist.gov/public_affairs/releases/PBDE_dust.htm.
Reference Source 128
January 11, 2005