Health risk assessment of trihalomethanes in drinking water in some cities of China: a literature study

  Objective  To examine the level of trihalomethanes (THMs) in drinking water and its potential health risk in some cities of China.

  Methods  We systematically retrieved the literatures published during 1997 – 2018 to obtain information on THMs concentration in drinking water in cities of China. For a total of 551 literatures in Chinese and English retrieved, 53 were included in the analysis. Health risk assessment model recommended by United States Environment Protection Agency (US EPA) was adopted in the assessment on the health risk of THMs in the drinking water for urban populations in China.

  Results  Four kinds of THMs were detected in drinking water in 20 cities in China, including chloroform (TCM), tribromomethane (TBM), dichloromonobromomethane (DCBM) and dibromochloromethane (DBCM). The non-carcinogenic health risk indexes were 0.023 for TCM, 0.0027 for TBM, 0.0061 for DCBM, and 0.0047 for DBCM; the carcinogenic risk indexes were 1.40 × 10 ^{– 6} for TCM, 4.3 × 10 ^{– 7} for TBM, 7.63 × 10 ^{– 6} for DCBM, and 7.93 × 10 ^{– 6} for DBCM, respectively.

  Conclusion  The non-carcinogenic health risk indexes are far less than one for THMs in drinking water in some cities in China but the carcinogenic risk indexes of the THMs are higher than those recommended by US EPA, suggesting that attentions should be paid to health risk related to THMs in drinking water.