CHARACTERISTICS OF POLYCYCLIC AROMATIC HYDROCARBON FORMATION DURING SMOKING

Abstract

This study examines the concentrations of polycyclic aromatic hydrocarbons (PAHs) in
cigarettes and sidestream cigarette smoke. All 16 gas-phase PAHs and fourteen particulate-phase PAHs were
determined in sidestream cigarette smoke for four brands of cigarettes. The median total of gas-phase and
particulate-phase PAH concentrations after two cigarettes were smoked were 79.6 ng/m3 and 10.0 ng/m3, and
the concentrations were several times higher than before smoking. Median PAH increases in the air samples
were 1050 ng per cigarette for gas-phase PAHs and 228 ng per cigarette for particulate-phase PAHs. Gas–
particle partition coefficients (Kp) of PAHs in air samples before and after smoking were correlated with the
subcooled liquid vapor pressures (PLº) of PAHs. The slopes of log-log plots of Kp versus PLº before and after
smoking were -0.270 and -0.575, respectively. PAH partitioning between the gas and particle phases after
smoking was closer to equilibrium state because the slope was closer to -1. Furthermore, all 16 PAHs were
determined in the cigarettes. The medians of total PAH concentrations in the four brands of cigarettes were
353 ng/g before smoking and 1130 ng/g after smoking. Median PAH increase in the cigarette samples during
smoking was 1410 ng per cigarette. The relationships in the concentration of the between total suspended
particulate (TSP) and total particulate-phase PAHs, and between total gas-phase PAHs and total particulate-
phase PAHs were significantly positive. These findings imply that lowering the amount of TSP generated will
lower the amounts of PAHs generated.