EXPOSURE TO TOXIC AIR CONTAMINANTS IN ENVIRONMENTAL TOBACCO-SMOKE - AN ASSESSMENT FOR CALIFORNIA BASED ON PERSONAL MONITORING DATA

The contribution of environmental tobacco smoke (ETS) to the exposure of adult nonsmoking Californians was determined for selected toxic air contaminants (TACs). The assessment was based an published measuremen ts of ETS emission factors and personal exposures to volatile organic compounds. The human exposure studies were conducted in three Californ ia areas - Los Angeles, Pittsburg/Antioch, and Woodland between 1984 a nd 1990. We derived unexposed and passive population exposure distribu tions by randomly sampling the monitoring results for individuals clas sified according to exposure status (active smoker, passively exposed, or unexposed to ETS during monitoring). The differences between the u nexposed and passive distributions were used to estimate the ETS-only contribution for exposure to benzene, styrene, o-xylene, and mg-xylene . Emission factors were then employed to infer the ETS-caused exposure to thirteen other compounds. The estimated arithmetic mean increments of 24-hour exposure attributable to ETS for the nonsmoking California n population (age greater than or equal to 7) exposed to ETS are as fo llows (results in units of mu g m(-3) exposure concentration; results using two different emission factors presented as a range): acetaldehy de 11-15; acetonitrile 7.0; acrylonitrile 0.49; benzene 1.02; 1,3-buta diene 0.75-2.3; 2-butanone 1.4; o-cresol 0.17; m,p-cresol 0.41; ethyl acrylate < 0.015; ethylbenzene 0.49-0.64; formaldehyde 6.5-8.2; n-nitr osodimethylamine 0.0028; phenol 1.4; styrene 0.36; toluene 3.1-3.2; o- xylene 0.77; m,p-xylene 0.99. The 90% confidence limits on these estim ates due to the limited sample size in the studies are roughly x/divid ed by 6. For four winery studied compounds, ETS is estimated to contri bute the following percentages to the total inhalation exposure of all nonsmoking Californians: o-xylene 5%; m,p-xylene 3%; benzene 5%; and styrene 8%.