Chloroform in food samples from 2014 Canadian total diet study: occurrence and dietary exposure

Chloroform or trichloromethane is one of the trihalomethanes formed during disinfection of water with chlorine, and residues of chloroform can be detected in foods and food products due to the use of chlorinated drinking water and disinfecting food processing equipment with chlorine-based disinfectants. In this study, chloroform was detected in 37 (or 23%) of the 159 composite food samples from the 2014 Canadian Total Diet Study, but was not detected in cereals, fruits, fast foods, and most of the meat samples. Chloroform was detected in almost all 14 composite samples of dairy products, with the highest level (58 ng/g) observed in butter, followed by cream (26 ng/g), and cheese (12-21 ng/g). Chloroform was detected in tap water (23 and 29 ng/g) and most of the beverage samples, but concentrations were lower than those reported in other studies possibly due to evaporation during the preparation of the composite samples. Dietary exposures to chloroform are higher for younger age groups (0.51-1.41 mu g/kg body weight/day) than for adults (0.25-0.42 mu g/kg body weight/day). Drinking water contributed most to daily intakes for all age groups, accounting for between 62% and 86% of the total chloroform dietary intakes.