By Harder, B.
Science News , Vol. 170, No. 6
A chemical in some air fresheners and pestcontrol products may slightly impair lung function in millions of people, a nationwide study suggests.
The compound, para-dichlorobenzene, is used to make mothballs, urinal deodorizers, and air-freshening blocks for household use. At room temperature, the strong-smelling chemical gradually changes from a solid to a gas.
Para-dichlorobenzene was previously detected in the blood of more than 95 percent of the participants tested in a U.S. study called NHANES III.
Scientists at the National Institute of Environmental Health Sciences in Research Triangle Park, N.C., looked for effects of the chemical and 10 other volatile organic compounds commonly detected in U.S. residents. Led by internist and epidemiologist Stephanie J. London, the team analyzed NHANES III data from 953 adult volunteers.
The researchers compared the recorded blood concentrations of each of the 11 chemicals to several measures of lung function, including forced expiratory volume in 1 second (FEV1). They also considered related factors, such as exposure to cigarette smoke.
The tenth of the study's participants who had the most para-dichlorobenzene in their blood--more than 4.4 micrograms per liter--had about 4 percent lower FEV1 values than did the tenth of participants with the lowest blood concentrations--averaging 0. …