Risk Assessment of Ingestion of Arsenic-Contaminated Water among Adults in Bandlaguda, India

Background. The Indian Government describes the Patancheru Industrial Development Area (IDA) near Hyderabad as a heavily polluted site. Previous studies show levels of arsenic in ground and surface water that exceed the national drinking water standard. Objectives. We conducted a pilot study to characterize potential non-cancer and cancer risks associated with ingesting arsenic-contaminated water by adult residents of Bandlaguda, a village in the Patancheru IDA. Methods. We used United States Environmental Protection Agency (USEPA) equations to calculate hazard quotients (for non-cancer outcomes) and excess cancer risks. Inputs included information on water sources and consumption that we collected from a representative sample of residents using a standardized questionnaire, and arsenic concentration data from a previous study. We calculated point estimates of risk and used @RISK software to conduct probabilistic simulations and perform sensitivity analyses. Results. In both the point and probabilistic analyses, the mean hazard quotients exceeded 1 for both men and women, indicating potentially elevated risk of non-cancer outcomes. Mean lifetime excess cancer risks using the USEPA default 70-year life expectancy were 0.01 (i.e., 1 in 100) for men and 0.006 (i.e., 6 in 1,000) for women. Mean excess risks using Indian life expectancies were 0.01 for men and 0.007 for women. Sensitivity analyses identified the reference dose and cancer slope factor as the most influential input variables. Conclusions. Our results show that arsenic in water consumed by Bandlaguda adults may be associated with both non-cancer and cancer risks. There is an urgent need to identify unsafe sources of drinking water in this community and educate residents on the hazards of using them.