532 SERUM COTININE MEASURES PASSIVE SMOKING IN YOUNG CHILDREN

Abstract

Investigating the health consequences of passive smoking would be aided by a quantitative measure of tobacco smoke exposure. We studied whether cotinine, the major metabolite of nicotine, could be detected by radioimmunoassay in the serum of young children and used as a measure of household exposure to tobacco smoke. Our subjects were 46 healthy children, aged 7 months to 5 years, in a group day care center. After a serum sample was obtained from each child, a telephone smoking questionnaire was administered to the child's parents. Serum cotinine proved to be a valid indicator of passive smoking in these children. Median cotinine concentration was 4 ng/ml (range 0 to 11 ng/ml) in exposed children and 0 ng/ml (range 0 to 4 ng/ml) in unexposed children (p<.0001). Serum cotinine correlated well with the reported total number of cigarettes consumed daily in each child's home (r=.69, p=.0004). Serum cotinine concentration can be used as a measure of exposure in studies of the long term health consequences of tobacco smoke inhalation in early life.