“…These findings are comparable with a related meta-analysis performed by Morris et al [ 49 ], which showed that chlorinated surface water has significantly more chlorination by products than chlorinated groundwater (medians of 50.7 and 0.8 ppb, respectively). Therefore, the consumption of surface water was found to be an indirect proxy of exposure to disinfection by products used in associated studies [ 50 , 51 ].…”