Sources of Fine Organic Aerosol. 6. Cigarette Smoke in the Urban Atmosphere

Molecular marker compounds that can be used to trace cigarette smoke particles in the outdoor urban atmosphere are identified. While the most abundant resolved organic compounds present are nitrogen-containing heterocyclics (e.g., nicotine), other potential tracers that will be more stable in the outdoor urban atmosphere also are found. Iso- and anteisoalkanes (C₂₉-C₃₄) are enriched in cigarette smoke particles and show a concentration pattern characteristic of tobacco leaf surface waxes that is distinctly different from leaf surface abrasion products shed from plant leaves that grow in the Los Angeles area. Relative to major leaf surface wax n-alkanes, these iso- and anteisoalkanes are enriched by a factor of more than 40 in tobacco and tobacco smoke particles as compared to leaf surface waxes from Los Angeles area plants. It is found that the iso- and anteisoalkanes concentration pattern generated by cigarette smoke is preserved in the urban atmosphere and is measured at levels that are comparable to emissions estimates based on daily cigarette consumption. Using these marker compounds, ambient fine cigarette smoke particles are estimated to be present at a concentration of 0.28-0.36 µg m^-3 in the Los Angeles outdoor air, accounting for 1.0-1.3% of the fine particle mass concentration.