Stung Lung: Volatile chemical may cut respiratory capacity Ben Harder A chemical in some air fresheners and pest-control 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...