A chemical found in air fresheners, toilet deodorizers,
and mothballs -- and in the blood may harm the
The finding comes from a National Institutes
of Health study that measured lung function and
blood levels of 11 household chemicals in 953
U.S. adults. All 11 chemicals are volatile organic
compounds -- chemicals given off as gasses from
common household products.
Only one was linked to lung damage: 1,4-dichlorobenzene
or 1,4-DCB. You know what it smells like -- mothballs.
It's most often used in room deodorizers, urinal
and toilet-bowl blocks, and, yes, mothballs.
The 10% of people with the highest blood levels
of 1,4-DCB did 4% worse in a test of lung function
than the 10% of people with the lowest blood levels
of the chemical, found Stephanie J. London, MD,
and colleagues at the National Institute of Environmental
Health Sciences (NIEHS).
The researchers called this a "modest reduction"
in lung function. But they warn it could be serious
for people who suffer asthma
or other lung problems. And the reduced lung function
test linked to 1,4-DCB is also a risk factor for
cancer, and death from any cause.
"Even a small reduction in lung function may
indicate some harm to the lungs," London said,
in a news release.
A 2005 study found that the risk of asthma in
children age 6 months to 3 years goes up as their
home 1,4-DCB exposure increases.
"This research suggests that 1,4-DCB may exacerbate
respiratory diseases," said NIEHS director David
A. Schwartz, MD, in a news release.
In some homes and public restrooms, the CDC has
detected 1,4-DCB levels that exceed the Environmental
Protection Agency's minimal risk limit for long-term
London suggests that people can limit their exposure
to 1,4-DCB by reducing their use of products containing
the chemical. But that may not be entirely successful.
A 1987 study by the Environmental Protection
Agency found 1,4-DCB in the air of 80% of U.S.
homes surveyed. Only a third of these homes used
products containing the chemical.
The new findings appear in the August issue of
Environmental Health Perspectives.