Health risk assessment of volatile organic compounds emitted from wastewater treatment plants in Tapioca industry

Tapioca starch production is one of an important agro-industry in Thailand. Wastewater generating from starch processes can emit large amount of air pollutants. In order to evaluate human effects of air pollutants emit from tapioca wastewater treatment plant, health risk assessment was performed in this study. Twenty-one VOC species were found in air samples collected by the closed chamber experimental study and analyzed for their speciation using GC/MS analysis. Four dominant VOCs were partly odorous compounds. After that 9 VOCs categorized as carcinogenic and non-carcinogenic substances by the IARC were selected for the health risk analysis. The total non-carcinogenic risk was approximately 0.151, 0.005 for workers and general public, the value is lower than one which no poses a threat to human health. The carcinogenic risk of benzene for workers and general public were 2.84 × 10-7 and 1.17 × 10-10 respectively. These values were much lower than an acceptance level. It is estimated to pose no health hazard. As a result, it can be concluded that there are some odor nuisance problem caused by air pollutants released from wastewater treatment system of the tapioca starch production factory. This finding determines the necessity in improving and managing of existing wastewater treatment system in order to minimize nuisance problems.