Disinfection By-products Tendency and Carcinogenic Risk in Treated Water in Wuxi

Objective To investigate the tendency and carcinogenic risk of disinfection by-products(DBPs) in treated water in Wuxi.

Methods Water samples were collected from 4 waterworks in Wuxi during the period of August 2008 to August 2012. Four halomethanes(THMs) and two chloro-haloacetic(chloro-HAAs) were monitored. The carcinogenic risk was evaluated by the method recommended by the US Environmental Protection Agency(USEPA).

Results The level of DBPs met the national standards for drinking water(GB 5749-2006). There was an obvious seasonal variation of THMs, which were higher in high flow period than in low flow period. No significant variation was observed for HAAs. The carcinogenic risks of DBPs in Wuxi were all over the negligible levels recommended by USEPA. The rank of DBP levels in water was CHCl₃O₂ > C₂H₂Cl₂O₂ > CHBr₂Cl > CHBr₃ > CHBrCl₂ > CHCl₃.

Conclusions The level of THMs from treated water in Wuxi were changed greatly with seasonal variation. There was a potential carcinogenic risk of DBPs to adults in Wuxi city.