Abstract
A cross-sectional study of 50 participants was performed to investigate benzene exposure in an urban Mediterranean climate. Participants wore passive samplers for five 24-hour periods in each of summer and winter (including weekends), and recorded their locations and activities during sampling in a time/activity diary. Statistical analysis using a linear mixed model revealed that commuting in a private car (β= 0.281, p<0.0001) and refuelling with low benzene fuel (β = 0.194, p=0.033) were significant contributors to non-industrial personal exposure. The mean benzene exposure of the participants in summer was 1.76 μg m-3 and 1.98 μg m-3 in winter. Each hour per day spent commuting resulted in a mean increase in personal exposure of 0.74 μgm-3 (β= 0.729 μgm-3, p< 0.0001). Reported refuelling with low benzene fuel increased exposure by 1.50 μgm-3 (1.49, p<0.0001) in each 24-period when refuelling was reported. A risk assessment of these activities in Perth was conducted using the World Health Organisation unit risk model. Unit risk is a measure of the lifetime excess cancer risk posed by a lifetime exposure to a pollutant at a concentration of 1μg m-3. When applied to these two activities, the World Health Organisation risk model revealed that they pose a high risk over an individual's lifetime compared to the unit risk of 6 cases per million population exposed to 1μgm-3. The results of this research highlight the high cancer risks posed by these activities when compared to most other routine types of activities of indoor and outdoor activities that occur on a daily basis, and the need for appropriate environmental management to effectively manage and mitigate the risks these activities pose to the general public.