Airborne Volatile Organic Compounds and Their Potential Health Impact on the Vicinity of Petrochemical Industrial Complex

The aggregate potential health impact due to ambient volatile organic compounds on the population living in the area nearby the petrochemical industrial complex in Thailand was evaluated using measured air contaminants concentration. Airborne volatile organic compounds were collected using canisters and were analyzed by gas chromatography/mass spectrophotometer following the US.EPA TO 15 procedure. Composite samples taken over a 24-h period were collected monthly. Concentrations of volatile organic compounds (VOCs) were analyzed for a suite of 24 compounds covering both carcinogenic and non-carcinogenic substances. Results were determined and analyzed in order to evaluate their spatial variability and their potential health risk. Comparison of data from each monitoring site indicated that patterns of VOCs across sites were different from their major species and their concentrations which might be influenced by nearest potential emission sources. Carcinogenic VOCs such as benzene, 1,3butadiene, and 1,2 dichloroethane were found to be higher than their annual national standards. A potential cancer risk map was drawn based on benzene concentration in order to illustrate the zone of impact and the number in the population likely to be exposed. Results indicated that 82% of the total area, and 89.6% of the total population were within the impact area. It was suspected that high concentrations of benzene and 1,3 butadiene might be attributed by both the mobile source and the point source of emissions while 1,2 dichloroethane was suspected to be emitted from factories located upwind from the monitoring sites. Hazard quotients and hazard indexes were applied to determine chronic health effects with non-cancer endpoints. Calculated values of hazard indexes for each of the target organ systems were lower than 1, which indicated that the non-cancer chronic risk due to level of volatile organic compounds in the study area was less.