Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters

Abstract

Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired power plants, conventional oil and gas extraction, textile mills, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. We estimate bladder cancer risk from potential increased bromide levels in source waters of disinfecting public drinking water systems in the United States. Bladder cancer is the health end point used by the United States Environmental Protection Agency (EPA) in its benefits analysis for regulating disinfection byproducts in drinking water. We use estimated increases in the mass of the four regulated trihalomethanes (THM4) concentrations (due to increased bromide incorporation) as the surrogate disinfection byproduct (DBP) occurrence metric for informing potential bladder cancer risk. We estimate potential increased excess lifetime bladder cancer risk as a function of increased source water bromide levels. Results based on data from 201 drinking water treatment plants indicate that a bromide increase of 50 μg/L could result in a potential increase of between 10(-3) and 10(-4) excess lifetime bladder cancer risk in populations served by roughly 90% of these plants.

Web‐Based Applications to Simulate Drinking Water Inorganic Chloramine Chemistry

“…For context, 0.115 mg/L bromide represented the 90th‐percentile value among large (serving more than 10,000 customers) surface water plants (USEPA ). The incorporation of bromide chemistry is a future research need as bromide sources include brackish water, desalination sources, and upstream bromide‐laden discharges (Regli et al ).…”

Disinfection Processes

“…Health Risk Assessments. Based on data from 201 drinking water treatment plants, 50 g/L increases in bromide concentration in source waters were predicted to increase the mass of regulated THMs and estimated to increase excess lifetime bladder cancer risk by 10 -3 and 10 -4 in populations served by 90% of these plants (Regli et al, 2015). In models of health risks from THMs from toilet flushing, carcinogenic risk was greater than noncarcinogenic risk, and dibromochloromethane had the greatest impact on risk .…”

Re‐assessing effects of bromide and granular activated carbon on disinfection byproduct formation

“…Ozonation of water containing bromide forms bromate (Gunten & Hoigne, 1994;Haag & Hoigne, 1983), which is also a regulated DBP. Recently, concerns have been raised over the increasing concentrations of Br-DBPs as a result of increased bromide levels in drinking water sources (Good & VanBriesen, 2016;McTigue, Cornwell, Graf, & Brown, 2014;States et al, 2013) and potential public health risks (Regli et al, 2015;Richardson et al, 2007;Sawade, Fabris, Humpage, & Drikas, 2016).…”