Human health risk assessment of arsenic in groundwater aquifers of Lahore, Pakistan

The present study was conducted to estimate As concentration in groundwater and resulting human health risk in terms of chronic daily intake, hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR) both for oral and dermal exposure to As. Groundwater samples (n = 100) were collected from ten different towns of Lahore District (Pakistan). Arsenic concentration ranged from 2 to 111 mu g L-1 in groundwater samples of the study area, which was significantly greater than the safe limit of As (10 mu g L-1) in drinking water set by the World Health Organization. Health risk assessment of As showed that HQ (0.1-11) for oral exposure and HI (0.1-11) values also exceeded the typical toxic risk index value of 1. 9.75 x E-05-4.59 x E-03 and 5.89 x E-07-2.77 x E-05 for oral and dermal As exposure, respectively. Both CR and cancer index (CIs) values were higher than United States Environmental Protection Agency limit (10(-6)), suggesting that people are at high risk of As-induced carcinogenicity from oral and dermal exposure to As in drinking water. It was concluded that As contamination of groundwater causes carcinogenic and noncarcinogenic health effects to the people; therefore, urgent management and remedial actions are required to protect people from As poisoning.