Objectives：The aims of this study were to investigate the exposure of volatile organic compounds (VOCs), to clarify the contribution of volatile organic compounds from industries and traffic, and to perform health risk assessment on residents in the vicinity of Central Taiwan Science Park.
Method：Four roads linked to outsides of this park were selected as five sites to measure the volatile organic compounds emitted from the traffic. Area with the estimated maximum concentration by ISC-ST3 model and adjacent to communities within 3 km of this park were determined as five eligible places to conduct the environmental sampling. Sampling and analysis method are followed TO-14 adopted by the U.S. EPA. We performed 12-hour air sampling by using 10 canisters seasonally. These samples were subject to qualitative and quantitative analyses by using the GC/MS. The chronic hazard index (HIc) and the cancer risk were used to assess the non-carcinogenic and carcinogenic risks of volatile organic compounds for residents.
Results：We found the average concentration of total VOCs increased from 127±68 ppbv in spring to 163±146 ppbv in autumn but decreased with 49±28 ppbv in winter dramatically. Among 7 VOCs related to industry emission, two of ethanol and cyclohexanone had the raising concentration from spring to winter. Acetone and isopropyl alcohol had the raising concentration observably from spring to autumn but reduced in winter. Other three had no consistent trend seasonally. In contrast, only the average concentration of toluene had the obvious increment compared to 7 VOCs related to traffic emission during the study period. We estimated that residents in the vicinity of Central Taiwan Science Park had the HIc for the neverous system between 0.27 to 1.07 by exposing to benzene, toluene, ethylbenzene, m/p-xylene, o-xylene, styrene, MTBE and IPA. Cancer risks of these residents were estimated at 2.0×10-5~8.3×10-4 by exposing to benzene.
Conclusions：Residents in the vicinity of Central Taiwan Science Park have the unacceptable noncancer risk for the neverous system and have the estimated cancer risk above the acceptable level (1×10-6) before the operation of this park. We suggest that the precise exposure assessment and prolonged monitor should be performed to assess the potential non-cancer and cancer risk among these residents.
