(VCCEP) Tier 1 Pilot Submission for BENZENE - Tera

Because there is considerable uncertainty associated with the exposure estimates currently
available, reasonable estimates of typical and high-end benzene exposures from use of small
engine equipment by children and prospective parents cannot be made at this time.
7.2.2.2 Tobacco Smoke
Benzene concentrations in the homes of smokers and nonsmokers were measured by Wallace
et al. in the 1980s. At that time, the median level of benzene in 300 homes with one or more
smokers was 3.5 µg/m 3 more than the median level of benzene in a group of 200 homes without
smokers. A similar increase was reported by Heavner et al. (1995). Raw data from Adgate et
al. (2004b) were also analyzed to evaluate the impact of ETS on indoor air levels. Figure 7.5
compares the indoor air benzene levels measured by Adgate et al. (2004b) in smoking and nonsmoking
households. Because there was little or no difference in benzene air concentrations in
homes with attached garages regardless of the presence of a smoker, only homes without
attached garages were considered in this analysis.
Benzene VCCEP Submission
March 2006
Figure 7.5: Comparison of Indoor Air Concentrations of
Benzene in Smoking and Non-Smoking Households
Benzene Air Concentration
(ug/m3)
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
Smoking
Household
137
Non-smoking
Household
Homes Without Attached Garage
Min
Max
Average
Median
As shown in Figure 7.5, the smoking households from Agate et al., 2004b had slightly higher
average indoor air benzene concentrations than non-smoking households. The smoking
households had an average benzene concentration of 6.3 µg/m3 and non-smoking households
had an average benzene concentration of 3.8 ug/m3. The difference of 2.5 µg/m3 is lower than
that measured by Wallace et al. in the 1980s. This could be due to lower rates of smoking or
reduced ambient benzene concentrations.
Benzene is present in both the mainstream tobacco smoke inhaled by the smoker directly from
the cigarette and sidestream smoke released to the environment from the smoldering end of a
cigarette. Wallace (1996) found for non-smokers that environmental tobacco smoke (ETS),
which is comprised of both sidestream smoke and exhaled mainstream smoke (Daisey et al.,
1994, NAP, 1986) was responsible for 10% of exposure to benzene in the late 1980s. For
smokers, Wallace indicated that 89% of benzene exposure is due to inhaled mainstream
smoke, and 2% due ETS.