P-DICHLOROBENZENE EXPOSURE AMONG 1,000 ADULTS IN THE UNITED-STATES

p-Dichlorobenzene is used widely in the United States as a room deodor izer, a moth repellent, and a precursor for a polymer. In a previous s tudy of selected children in Arkansas, we found that 96% of the childr en had detectable urinary concentrations of 2,5-dichlorophenol, the me tabolite of p-dichlorobenzene. In the current study, we found that, in a sample of 1 000 adults who lived throughout the United States, 98% had detectable levels of 2,5-dichlorophenol in their urine, and 96% ha d detectable levels of p-dichlorobenzene in their blood. Urinary 2,5-d ichlorophenol concentrations ranged up to 8 700 mu g/l (median and mea n concentrations of 30 mu g/l and 200 mu g/l, respectively). p-Dichlor obenzene blood concentrations ranged up to 49 mu g/l, with median and mean concentrations of 0.33 mu g/l and 2.1 mu g/l, respectively. The P earson correlation coefficient for 2,5-dichlorophenol in urine and p-d ichlorobenzene in blood was .82 (p<.0001), thus demonstrating a strong association between these exposure measurements. Neither age nor gend er was related to urinary 2,5-dichlorophenol or blood p-dichlorobenzen e concentrations (p>.40). When these results are viewed with data from other studies, the collective data show that p-dichlorobenzene is a c ommon, worldwide contaminant. The high prevalence of exposure to p-dic hlorobenzene, coupled with its potential for adverse health effects, i ndicate the need for more detailed studies, including studies of long- term health effects on exposed populations.