Human Health Risk Assessment for Drinking Water Contaminated with Volatile Organic Compounds

Though water is one of the most important compounds to sustain life, contaminated drinking water is a source of many illnesses. Drinking water contaminated with volatile organic compounds may lead to liver and Kidney damage, immune system, nervous system, and reproductive system disorders as well as several types of cancers. Volatile organic compounds (VOCs) are carbon based chemicals that easily evaporate into gaseous state at room temperature. So, they are much more mobile and more likely to be released to the environment. These compounds are released into the environment during their production, storage and use, and can enter both ground water supplies and surface water bodies. VOCs are found in everyday household items such as paints, glues, fuels, paint strippers, aerosols, varnishes, lacquers, wood preservatives, craft kits, cleaners pesticides, cigarette smoke and dry cleaned clothes. Benzene, toluene, p-xylene, and naphthalene are the most frequently detected VOCs. The process practiced in drinking water treatment plants (i.e. disinfection) and the chemical added to the water for specific treatment may result in production of specific VOC species such as trihalomethanes (THMs). THMs are by products of disinfection, produced in drinking water treatment plants by the reaction between the natural organic matter present in raw water and the chemicals added as disinfectants, especially chlorine. Chloroform, bromodichloromethane, dibromochloromethane, bromoform etc. are the most common types of THMs.

In this present work, the carcinogenic and noncarcinogenic risks will be characterized for the volatile organic compounds in drinking water employing both deterministic and probabilistic approaches. A comparison between the results for these two approaches will also be studied through a case study.