Polycyclic Aromatic Hydrocarbons, Organochlorine Pesticides And Heavy Metals In Mainstream Cigarette Smoke

The main hazardous matters in tobacco smoke include nicotine, carcinogenic matters such as polycyclic aromatic hydrocarbons (PAHs), carbon monoxide, heavy metals, cilia matters such as volatile aldehyde and organochlorine pesticides (OCPs). China, topped in tobacco consumption in the world, should pay more attention to the pollution and health effects arising from smoking. In the present study, 15 brands of popular commercial cigarettes sold in China, including ten baked types and five mixed types, were selected for the analysis of hazardous matters in mainstream smoke. The particulate matters in mainstream smokes were collected with Cambridge filters using an automated smoking machine, and 65 PAHs (including 16 USEPA priority PAHs), 17 OCPs and 45 heavy metals were analyzed with GC-MS, GC and ICP-MS, respectively. Main conclusions were drawn from the study as the following:Total levels of the 65 PAHs varied among different brands of cigarette. Naphthalene has the highest levels among the 16 priority PAHs, and light molecular weight PAHs were dominant in the PAHs. Benzo[a]pyrene (BAP) were found to be in good correlations with total levels of the 16 priority PAHs, total carcinogenic PAHs and total BAP-equivalent carcinogenic potency, suggesting that BAP was a good marker of hazardous PAHs in mainstream smokes. BAP levels in baked types were higher than those in mixed types, but the BAP levels normalized with total particulate matter were lower in some baked types than in mixed types. PAH diagnostic ratios, including anthracene/(anthracene+phenanthrene) (ANT/178), fluoranthene/ (fluoranthene + pyrene) (FLT/202), benzo[a]anthracene / (benzo[a]anthracene +chrysene) (BAA/228) and indeno(1,2,3-c,d)pyrene / [indeno(1,2,3-c,d)pyrene + benzo(g,h,i)perylene] (IND/276) with the values 0.27, 0.53, 0.37 and 0.62, respectively, were used to distinguish ETS from other major indoor PAH sources, and FLT/202 was found to be a good marker identifying environmental tobacco smokefrom other indoor PAH sources.Seven OCPs were present in mainstream smoke. DDT was detected in most cigarette brands. Also DDT levels in Chinese brands were higher than those in foreign brands. DDE and DDD as degradation products of DDT, however, were seldom detected. This indicates that DDT pesticides may be newly used during growing tobacco in China. B-HCH was present in six cigarette brands, but other three isomers of HCH were not found in mainstream smoke. The detected B-HCH might be resulted from degradation of HCH residues taken up from soils and air, and possibly not from newly use of HCH pesticides.The levels of selected trace heavy metals in mainstream smoke varied among different cigarette brands. The concentrations of Ti, Ga, As and Sr in mainstream smoke were high in most brands, and Ge, Cs, Tl were low in most brands. The levels of eight important heavy metals (Cr, Co, Cu, As, Cd, Hg, Tl, Pb) and their totals in mixed brands were lower than those in baked brands. Different tobacco producing areas and tobacco manufacturing processes may be the main reason for these differences. There were good correlations between Cr and the total levels of the eight heavy metals, suggesting that Cr was a good indicator of hazardous heavy metals in mainstream smoke.