Abstract:
Environmental exposure to volatile organic compounds (VOCs) of workers in 11 gas station in Bangkok was assigned to study. The sampling using passive gas tube containing activated charcoal was performed during 29 October to November 2008. The correlation between active sampling and passive sampling was examined and satisfactory correlation of 10 compounds could be found with the range of coefficient of determination (R2) between 0.7958 0.9681. Each sample was collected in gas station for 8 hours during 6 am 14 pm. Each sample was taken to extract with CS2, and to qualitative analysis by GC-FID. Thirty-nine VOCs could be found and 10 compounds of those, such as methyl-tertiary-butyl-ether(MTBE), benzene, isooctane, n-heptane, toluene, ethylbenzene, m,p-xylene, o-xylene, stylene, 3-ethylbenzene and decanal were mainly observed in all study areas with the ranges of638-1628, 308-852, 20-49, 140-401, 270-682, 10-27, 22-58, 11-20, 13-26 and 1.8-9.8 µg/m3, respectively. From all detectable VOCs species mentioned above five compounds could be estimated health risk, including MTBE, benzene, ethylbenzene, toluene and xylene. This estimation result reveals that cancer risk level of the workers exposure to MTBE and benzene were in the range of 2.41x10-5 1.18x10-4 and 3.42x10-4 1.23x10-3, respectively. These levels were higher than an acceptable risk level at 1x10-6. While that of their exposure to ethylbenzene was within an acceptable criteria. For non-cancer risk estimation, there was no increase risk for the workers exposure to toluene and xylene because the GQ were less than 1.