Risk Assessment of Dioxins in Cigarette Smoke

RISK ASSESSMENT OF DIOXINS IN CIGARETTE SMOKE 1,2 1 1 3 Teiichi Aoyama , Komichi Ikeda , Atsushi Takatori and Terry Obal 1 Environmental Research Institute Inc., Suite 4-1108, 4-5-26, Tokyo 141-0021, Japan 2 Faculty of Environmental and Information Studies, Musashi Institute of Technology, Yokohama City, Kanagawa Prefecture, 224-0015, Japan 3 HRMS Services Division, Maxxam Analytics Inc., 50 Bathurst Drive, Unit 12, Waterloo, Ontario N2V 2C5 Canada Introduction There is no doubt that smoking cigarettes is harmful to human health. If the dioxin concentrations in cigarette smoke reach or exceed the carcinogenic levels suggested by the US EPA, and further the toxicity levels reported by the World Health Organization (WHO), the detrimental effects of cigarette smoking are much more serious. In this research, we have analyzed the dioxin concentrations in 5 major brands of cigarettes from Japan and the United States. Dioxin, furan and PCB congener concentrations were determined in the cigarette tobacco leaf, paper, ashes and filters. We then estimated the amount of dioxin TEQ in the smoke of the cigarettes, as well as the risk of human intake by smoking. Methods and Materials In order to research the risks associated with cigarette smoking, the analysis of dioxins in the 1,2 smoke is necessary. Based on our detailed review of previous work , we understand that, technically, it is very difficult to extract a direct sample of smoke generated from smoking, such as main and side-stream smoke. Therefore, conventional automatic smoking equipment (smoke generator) was used. However, it should be noted that sample extraction by this automatic equipment does not necessarily reflect actual human smoking conditions. Further we have estimated the movement of the dioxin TEQ concentrations between the leaf of the 1,3,4 cigarette, paper, ashes and filter before and after smoking as previously researched . For instance, 3 4 Miyata pointed out that “Matsueda et al estimated in their research that the dioxins generated by smoking is mostly contained in the main part (leaf and paper) of cigarette, and it vaporized at the time of smoking, shifted to the body by inhaling the mainstream smoke via a filter and also side stream smoke indirectly”. Subtracting the quantity of dioxins contained in the ashes and filter after smoking from the quantity of dioxins contained in the main part of the cigarette (leaf and paper) provides a close estimate of the dioxin concentration in the cigarette smoke. 1 Matsueda et al suggested in their research paper saying that even the mass balance of each parts of the cigarette (main part, butt, filters, ash, mainstream and side stream) were not perfectly balanced, it could be possible to substantiate that the dioxins in the mainstream could be derived from the cigarette leaf and paper (main part). Even though there might be some generation and destruction of dioxin in the process of combustion during smoking, the experimental data shows that dioxin levels of cigarette leaf and paper (main part) were much higher compared to the total dioxin levels of each part obtained by smoke generation experiment. Therefore, the dioxin concentration in the smoke (d) can be calculated by subtracting the sum of the dioxin concentrations in the filter after smoking (b) and in the residues/ash (c) from the original concentrations determined in the leaf and paper before smoking (a), as follows: (d) = (a) –[(b) + (c)] Formula 1 As for the quantity of sample used per brand, about 200 cigarettes were used for main parts, 60 i.e., leaf and paper, and about 160-370 50 Co-PCB cigarettes were smoked to collect the ash and 40 PCDF filter samples. All samples of ash and filter 30 PCDD were collected from cigarettes smoked by 20 10 people in the office of Weekly Magazine. To 0 determine dioxin TEQ concentrations in this MILD Marlboro KENT 1mg LARK Seven Stars SEVEN LIGHTS MILDS research, PCDDs, PCDFs and dioxin-like PCBs (Co-PCBs) analyzed. Maxxam (Main Parts: Leaf and paper) Analytics Inc. of Canada carried out the 6 analysis of dioxins. The analytical method 5 was based on EPA Method 8290B. Toluene 4 was used as the solvent for extracting the Co-PCB 3 PCDF main part of the cigarette samples, and PCDD 2 hydrochloric acid was used to facilitate the 1 extraction of ashes and filters. 0 Results and Discussion MILD Marlboro KENT LARK Seven (1) Analysis results SEVEN LIGHTS 1mg MILDS Stars The analytical results for dioxins, furans and (Ashes ) PCB congeners are shown in Figure 1. The 25 results are presented per one box (20 cigarettes). 20 (2) Verification by the Congener pattern 15 Co-PCB The congener patterns of dioxins for the 3 PCDF 10 PCDD different brands are shown in Figure 2. It turns out that there is a close correlation 5 between the congener patterns in the main 0 parts (leaf and paper) of the cigarette and the MILD Marlboro KENT 1mg LARK Seven Stars SEVEN LIGHTS MILDS filters by brand. It appears that the dioxins in the main parts have moved to the filter as (Filters after smoking) estimated in the hypothesis. We also found Fig.1 Dioxins in 1box of cigarette that the congener patterns of the main parts 1,2 and the filter were also quite similar, as reported in previous research papers . Additionally, the congener pattern in the smoke (mainstream and side stream) is also similar to the main parts and 1,2 filters . This correlation of patterns is also observed for the dioxin-like PCBs. However, the quantity of dioxin-like PCBs captured by the filter was small compared to PCDDs/PCDFs. pg-TEQ/20cigarettes pg-TEQ/20cigarettes pg-TEQ/20cigarettes 70 (3) Trial calculation of the amount of dioxins In main and side stream smoke, Figure 3 shows the variation of dioxins levels (pg TEQ/20 cigarettes) before and after smoking. As for both Mild Seven and Marlboro LIGHTS, figure 3 shows that the filter removes about half of the dioxins in the leaf and paper parts. On the other hand, KENT 1mg, Lark MILDS, and Seven Star showed significantly lower removal of dioxins by the filter. In order to evaluate the health risk of smoking here, the total amount of the dioxins contained in mainstream and side stream smoke was estimated. MILD SEVEN - leaf and paper 0 10 20 30 40 50 MILD SEVEN - filter 60 pg/g 0 T4CDDs P5CDDs H6CDDs H7CDDs OCDD T4CDDs P5CDDs H6CDDs H7CDDs OCDD T4CDFs P5CDFs H6CDFs H7CDFs OCDF T4CDFs P5CDFs H6CDFs H7CDFs OCDF 10 Marlboro LIGHTS - leaf and paper 0 10 20 30 40 50 60 pg/g 0 T4CDDs P5CDDs H6CDDs H7CDDs OCDD T4CDFs P5CDFs H6CDFs H7CDFs OCDF T4CDFs P5CDFs H6CDFs H7CDFs OCDF 10 KENT 1mg - leaf and paper 10 20 30 40 40 50 60 pg/g 20 30 40 50 60 pg/g 50 60 pg/g KENT 1mg - filter 50 60 pg/g 0 T4CDDs P5CDDs H6CDDs H7CDDs OCDD T4CDDs P5CDDs H6CDDs H7CDDs OCDD T4CDFs P5CDFs H6CDFs H7CDFs OCDF T4CDFs P5CDFs H6CDFs H7CDFs OCDF Figure 2 30 Marlboro LIGHTS - filter T4CDDs P5CDDs H6CDDs H7CDDs OCDD 0 20 10 20 30 40 Congeners Pattern of Dioxin Analogues in Cigarette Samples Comparison of the Main parts and the Filters (MILD SEVEN, Marlborough LIGHTS and KENT 1mg) pg-TEQ/20 Cigarette (1 Package) Table 1 is the estimated maximum 60 concentration of dioxins in the 50 mainstream and side stream smoke after 40 Filter smoking one box of each brand of 30 Ash cigarettes (20 cigarettes). The calculations 20 Tobocco were carried out using Formula 1. As 10 shown in Table 1, the results for different 0 MILD Marlboro KENT LARK Seven brands differ by a factor of approximately SEVEN Lights 1mg MILDS Star 7, with the lowest being Marlboro LIGHTS (7pg-TEQ/box) and the highest Figure 3 TEQ Levels before and after smoking being KENT 1mg (48pg-TEQ/box). (4) Estimation of the human health risk Based on the estimated amount of dioxins in smoke, the daily intake of total dioxins from mainstream and side stream smoke was calculated. The results are shown in Fig. 4. In the case of KENT 1mg cigarettes, the concentration of dioxins in the mainstream and side stream smoke (0.96pg-TEQ/bwt/day) approaches the minimum TDI value (1-4pg-TEQ/kg body weight/day) proposed by WHO. 0.96 0.6 0.36 0.46 Seven Star LARK MILDS KENT 1mg 0.14 Marlboro Lights 1.0 0.8 0.6 0.4 0.2 0.0 MILD SEVEN References 1. Matsueda, et al., (1991) PCDD/PCDF in Smoking of Cigarette, Japan Society for Atmospheric Environment, pp.475 2. Shiozaki, et al., (1998) PCDD/PCDF in Tobacco, 7th, discussion meeting of Japan Society for Environmental Chemistry, 3. Hideaki Miyata, (1998) Detection of Dioxin in Cigarette, Japan Medical Journal, No.3860 4. Matsueda, Kuroki, Nakamura, et al., (1994) Organohalogen Compounds, 20, pp.331 pg-TEQ/kg･day Acknowledgments There are still many unresolved Table 1 Amount of Dioxins contained in Mainstream and Side Stream of Cigarette issues concerning dioxins in Unit: pg-TEQ /box (20 cigarettes) cigarettes and cigarette smoke. Main Parts Filter Ashes Mainstream + It is important to continue these (a) (b) (c) Side stream (d) studies to better understand, and 43 22 3.3 18 be aware of the risks associated M ILD SEVEN with smoking and exposure to M arlboro LIGHTS 16 7.3 1.7 7.0 58 6.2 3.8 48 cigarette smoke. We would like KENT 1mg 39 5.8 3.1 30 to express our gratitude to Mr. LARK M ILDS Tanaka and Ms. Tsubata of Seven Star 32 3.4 5.2 23 Weekly Friday Magazine for their extensive support of this research project including preparation of the samples. Figure 4 Estimation of Human Risk