Disinfection byproducts in Canadian provinces: Associated cancer risks and medical expenses

Cancer risk assessment on trihalomethanes and haloacetic acids in drinking water of China using disability-adjusted life years

“…For THMs, the average concentrations followed the order: TCM > BDCM > DBCM > TBM, while for HAAs, TCAA > DCAA, which was consistent with other studies [42][43][44]. The total concentrations of four THMs and nine HAAs ranged from 1.50 to 94.90 g/L (median value: 16.48 g/L) and from below the detection limit to 52.98 g/L (median value: 7.46 g/L), which were much lower than those reported for Canada and the United States [2,13]. TCAA and DCAA were found to be dominant among the nine HAA species in most of the samples, which on average accounted for 89.3% of the total HAAs (THAA).…”

“…TCAA and DCAA were found to be dominant among the nine HAA species in most of the samples, which on average accounted for 89.3% of the total HAAs (THAA). The dominance of TCAA and DCAA has also been reported in previous studies conducted in Canada and China [13,14].…”

“…Shower frequency (F) and shower duration (t) were estimated from the shower-habit survey data in one northern city (Shijiazhuang) and two southern cities (Ningbo and Xiamen) to characterize the big difference of shower-habit between northern and southern China. To minimize the biases of possible outliers, 10th, 50th and 90th percentile values of the survey data were used to generate triangular distributions [13].…”

“…After the year 2000, EPA proposed a mode of action (MOA) approach (a nonlinear approach) for the risk assessment on TCM, and set a threshold (0.01 mg/kg/day, equal to its RfD), considered protective against cancer risk [29]. However, most risk assessments on TCM still adopted its previous oral slope factor [9][10][11][12][13][14][15][16], which was developed by EPA under the default assumption of linearity and has been deleted. Currently, the majority of evidence and documents support a MOA based risk assessment for TCM [30][31][32].…”

“…However, chlorine reacts with natural organic matter to generate disinfection by-products (DBPs) during chlorination. So far, more than one thousand chlorinated DBPs have been reported [1], among which trihalomethanes (THMs) and haloacetic acids (HAAs) are the two most abundant classes on a weight basis [2], thus gaining particular attention and being regulated globally incidence through lifetime exposure [9][10][11][12][13][14][15][16]. Havelarr et al [17] calculated DALYs for renal cancer due to bromate, the major DBP in the ozone disinfection process.…”