Health risk analysis of benzene, toluene, ethylbenzene, and xylene (BTEX) in groundwater in Yogyakarta City, Indonesia

Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) are persistent and bio-accumulative compounds that occur in petroleum-based products. Benzene is categorized as a carcinogenic substance while ethylbenzene is potentially carcinogenic. One of the sources of BTEX contamination in the environment is gas stations. The leakage of underground storage tanks (UST) of gas stations is a potential source of groundwater contamination, while in many areas, it is the main source of daily water consumption. The long-term consumption of this BTEX-contaminated groundwater may generate health risks. This paper will present the health risk analysis of the consumption of BTEX-contaminated groundwater taken from dug wells near a gas station in Yogyakarta City which has a history of major leakage. Analysis of BTEX in groundwater samples has been already presented in the previous study. Data for intake calculation was acquired through questionnaires and interviews on water consumption patterns. Risk analysis was conducted for both the carcinogenic effect of benzene and the non-carcinogenic effect for all BTEX compounds. Health risk analysis on BTEX exposure in groundwater resulted in the Hazard Quotient (HQ) value for all compounds which were still less than one, meanwhile, the Excess Cancer Risk (ECR) for benzene was less than 10- 4 . The result indicates the low health risk associated with the consumption of BTEX-contaminated groundwater in the study area.