Health Risk Assessment of Drinking Source Water in Chongqing

It was studied that the concentration distributions of NH3-N,CN,As,Hg,Cr+6,Pb,Cd,Cu,F and hydroxybenzene in 8 samples of drinking source water in dry season in Chongqing City.Health risks associated in drinking source water were assessed with USEPA health risk assessment model.The results showed that the concentrations of the contamination in drinking source water in Chongqing ranged from 0.119~0.740mg/L for NH3-N,0.002~0.004 mg/L for CN,0.001~0.007 mg/L for As,0.000001~0.00005 mg/L for Hg,0.004~0.023 mg/L for Cr+6,0.004~0.053 mg/L for Pb,0.00035~0.005 mg/L for Cd,0.0005~0.0254 mg/L for Cu,0.140~0.335 mg/L for F,0.001~0.0027 mg/L for hydroxybenzene.Among the health risks caused by the non-carcinogens in drinking source water,the largest risk was the risk associated with Pb then followed by F,both in the levels of 10-8~10-9/a.Among the health risks caused by the carcinogens in drinking water,the largest risk associated with Cr+6 that ranged 10-4/a.It was in the range of EPA standard,while significantly high than maximum allowance levels recommended by ICRP.