Study of Eighteen Non-Smokers Occasionally or Chronically Exposed to Environmental Tobacco Smoke

Air nicotine content was sampled, using personal samplers, for 24-hour peri ods and measured using HPLC techniques together with nicotine and its main metabolites, free and conjugated, in urine collected from non-smokers: adults and children, variously exposed to environmental tobacco smoke (ETS). Assuming that the nicotine inhaled was completely retained by the non-smok er, the 'cigarette equivalent' dose (based on 1 mg nicotine/cigarette) could be estimated at between 0.005 and 0.29 (mean 0.11) cigarettes. Based on the sum of the concentrations of nicotine and its metabolites (expressed as nicotine) determined in urine of the non-smokers, elimination by this route was shown to be between 0 and 91 % (mean 41 %); the retained cigarette-equivalent (al though an approximate parameter) was then between 0.00 and 0.17 (mean 0.05) cigarettes. In our study, occasionally exposed adults excreted nicotine and its metabolites slowlier than those chronically exposed, while children exposed to parental smoking were less affected by ETS. Biotransformation of nicotine seemed to be more important with frequent repeated exposure to ETS. In all cases, absorption and retention of nicotine was low.