Cigarettes: Point Source for Benzene Exposure?

The correlations between passive smoking and benzene are very weak. This weakness is further demonstrated in another EPA report (7) that shows when the New Jersey and the California data for matched indoor and outdoor samples are regressed, only the first group of data for Los Angeles (LAI) show a significant correlation with the presence of a smoker in the home, and then only with p = 0.1 (probability that a smoker in the home was a significant variable). A later study conducted in Los Angeles (8), continuing primarily with the same homes at two different times of the year, was unable to show a significant difference between benzene in the air in the homes of smokers and those of nonsmokers. This result held true regardless of the season, the time of day, and the area of the house that was studied. What this later study did show was that the location of the outside samplers was important because there was not a good correlation between fixed or area samples and individual samplers located outside homes. This implies that the location of individual samples outside of homes is critical. We know of no published work in which this variable has been studied. Hence, when examining earlier data, the emphasis should be on matched indoor-outdoor results, and even then one should not be overly confident in the results. Wallace's Figure 2, which compares West German data to U.S. data, appears to contain an error. Krause et al. (S) give the concentrations of benzene in West German homes as 9.3 and 6.9 KJg/m3 for smoking and nonsmoking, respectively, not 11 and 6.5 pg/mi3 as quoted by Wallace. We are also suspicious of the practice of comparing two different statistics, i.e., U.S. geometric means and West German medians. We are aware of the breath levels of benzene in self-reported work exposure as discussed by Wallace et al. (10). Those results, obtained by the TEAM study in New Jersey when exhaust fumes infiltrated the van containing the spirometer, indicated that nonsmokers exposed to passive smoke more than 50% of the time at work could probably reduce their exposure by becoming smokers! Neither the experimental conditions during the New Jersey study nor the finding about the equivalent workplace exposure to benzene inspires much faith in the passive smoking conclusions from the TEAM study. Readers with a need to incorporate the results of the TEAM study …