Estimating trihalomethane concentrations in bottled spring water

Abstract

The chlorination of water has led to a substantial reduction in waterborne disease outbreaks. There are, however, concerns regarding the safety of trihalomethanes (major by-products of chlorination). One of the limitations of much of the existing evidence is the lack of individual trihalomethane exposure estimates, and these estimates should include the concentration of trihalomethanes in bottled water. In Australia, water advertised as ‘spring’ or ‘mineral’ water should, by definition, remain untreated, and should not, therefore, contain any trihalomethanes. We tested this assumption by assessing the concentration of trihalomethanes (bromodichloromethane, bromoform, chloroform, dibromochloromethane, and total trihalomethanes) in the six brands of bottled spring water most commonly consumed by pregnant women in Australia (here labelled A–F). For each water brand, two bottles were purchased from five locations, and this procedure was replicated approximately 2 weeks later. Standard water analysis techniques were used to determine the concentrations of bromodichloromethane, bromoform, chloroform, dibromochloromethane, and total trihalomethanes in each bottle. All 10 samples of brands A and B were positive for trihalomethanes, as was one bottle of brand C. No trihalomethanes were detected in any of the samples of the remaining three brands (D–F). The highest recorded total trihalomethane concentration was 30 µg/L. The trihalomethane concentration in Australian bottled spring water cannot be assumed to be zero. Studies estimating trihalomethane exposures should, therefore, collect data on the brand of the bottled water consumed, and test these brands contemporaneously for their trihalomethane exposures, to strengthen the evidence regarding trihalomethane exposure and human health outcomes.