title: Disinfection byproducts in Canadian provinces: associated cancer risks and medical expenses.
abstract: Chlorination for drinking water forms various disinfection byproducts (DBPs). Some DBPs are probably linked to human cancer (e.g., bladder, colorectal cancers) and other chronic and sub-chronic effects. This emphasizes the need to understand and characterize DBPs in drinking water and possible risks to human health. In this study, occurrences of DBPs throughout Canada were investigated. Trihalomethanes (THMs) were observed to be highest in Manitoba followed by Nova Scotia and Saskatchewan, while haloacetic acids were highest in Nova Scotia followed by Newfoundland and Labrador. Based on the characterization of DBPs, risk of cancer from exposure to THMs was predicted using ingestion, inhalation and dermal contact pathways of exposure. In Canada, approximately 700 cancer cases may be caused by exposure to THMs in drinking water. Medical expenses associated with these cancer incidents are estimated at some $140 million/year. Expense may be highest in Ontario (∼$47 million/year) followed by Quebec (∼$25 million/year) due to a greater population base. This paper suggests improvements in water treatment, source protection and disinfection processes, and caution in the use of alternative disinfectants to reduce DBPs. Finally, elements are provided to mitigate risks and reduce cost estimates in future studies.
authors.affiliation: Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. SChowdhury@kfupm.edu.sa
authors.forename: Shakhawat
authors.initials: S
authors.lastname: Chowdhury
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Rodriguez
authors.forename: Rehan
authors.initials: R
authors.lastname: Sadiq
mesh_terms: D002170:Canada; D017281:Cost of Illness; D004203:Disinfection; D004781:Environmental Exposure; D006801:Humans; D009369:Neoplasms / Q000139:chemically induced* / Q000191:economics; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical