CONTRIBUTION OF TOBACCO-SMOKE TO ENVIRONMENTAL BENZENE EXPOSURE IN GERMANY

The concentrations of environmental tobacco smoke (ETS) constituents i ncluding benzene were measured in the living rooms of 10 nonsmoking ho useholds and 20 households with at least one smoker situated in the ci ty and suburbs of Munich. In the city, the median benzene levels durin g the evening, when all household members were at home, were 8.1 and 1 0.4 mu g/m(3) in nonsmoking and smoking homes, respectively. The corre sponding levels of 3.5 and 4.6 mu g/m(3) were considerably lower in th e suburbs. Median time-integrated 1-week benzene concentrations in the city were 10.6 mu g/m(3) in nonsmoking homes and 13.1 mu g/m(3) in sm oking homes. In the suburbs, the corresponding values were 3.2 and 5.6 mu g/m(3). While the benzene concentrations in nonsmoking homes locat ed in the city were significantly higher (p < 0.05) than in suburban n onsmoking households, no difference was found between smoking and nons moking households located either in the city or in the suburbs. Indivi dual exposures to benzene and to specific markers for tobacco smoke of all household members (82 nonsmokers and 32 smokers) were determined by questionnaire, personal monitoring, and biomonitoring. Within the c ity, the benzene exposure determined by personal samplers was 11.8 mu g/m(3) for nonsmokers living in nonsmoking homes and 13.3 mu g/m(3) fo r nonsmokers in smoking homes. The corresponding values for nonsmokers living in the suburbs were 5.9 and 6.9 mu g/m(3), respectively. Neith er difference was statistically significant. Nonsmokers living in nons moking households in the city had significantly higher exposure to ben zene compared to their counterparts living in the suburbs (personal sa mplers: 11.8 vs 5.9 mu g/m(3), p < 0.001; benzene in exhalate: 2.4 vs. 1.1 mu g/m(3), p < 0.05; trans,trans-muconic acid excretion in urine: 92 vs. 54 mu g/g creatinine, p < 0.05). Nonsmokers from all household s with smokers were significantly more exposed to benzene than nonsmok ers living in the nonsmoking households (personal samplers: 13.2 vs. 7 .0 mu g/m(3), p < 0.05; benzene in exhalate: 2.6 vs. 1.8 mu g/m(3), p < 0.01; trans,trans-muconic acid excretion in urine: 73 vs. 62 mu g/g creatinine), but the contribution of ETS to the total benzene exposure was relatively low compared to that from other sources. Analysis of v ariance showed that at most 15% of the benzene exposure of nonsmokers living in smoking homes was attributable to ETS. For nonsmokers living in nonsmoking households benzene exposure from ETS was insignificant.