Department of Environmental Health Sciences, University of Michigan, Ann Arbor, 48109-2029, USA.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2009 Jul;26(7):947-57. doi: 10.1080/02652030902897739.
Trihalomethanes (THMs) are suspected carcinogens and reproductive toxicants commonly found in chlorinated drinking water. This study investigates THM formation during the preparation of beverages and foods using chlorinated drinking water. A total of 11 foods and 17 beverages were tested. Under the experimental conditions, each food and beverage formed THMs, primarily chloroform, although low or trace levels of brominated THMs were also detected. Tea formed the highest THM levels (e.g., chloroform levels from 3 to 67 microg l(-1)), followed by coffee (from 3 to 13 microg l(-1)), rice (9 microg l(-1)), soups (from 0.4 to 3.0 microg l(-1)), vegetables (<1 microg l(-1)), and baby food (<0.7 microg l(-1)). Chloroform formation with instant tea, used as a highly reproducible model system, increased with free chlorine concentration, decreased with higher food (tea) concentration, and was unaffected by reaction (steeping) time and bromide ion concentration. These findings indicate that chlorine-food reactions are fast, but that formation decreases as the chlorine demand of the food system increases. THMs are formed in the preparation and cooking of a wide variety of foods if free chlorine is present, and our results suggest that tea can be a significant source of exposure to THMs.
三卤甲烷（THMs）是常见于氯化饮用水中的可疑致癌物和生殖毒物。本研究调查了使用氯化饮用水制备饮料和食品过程中 THM 的形成情况。共测试了 11 种食品和 17 种饮料。在实验条件下，每种食品和饮料均形成了 THMs，主要是氯仿，但也检测到低浓度或痕量的溴化 THMs。茶形成的 THM 水平最高（例如，氯仿水平为 3 至 67 微克/升），其次是咖啡（3 至 13 微克/升）、米饭（9 微克/升）、汤（0.4 至 3.0 微克/升）、蔬菜（<1 微克/升）和婴儿食品（<0.7 微克/升）。用速溶茶作为高度重现性模型系统进行的氯代反应，随着游离氯浓度的增加而增加，随着食物（茶）浓度的增加而减少，不受反应（浸泡）时间和溴化物离子浓度的影响。这些发现表明，氯与食物的反应速度很快，但随着食物系统的氯需求增加，形成的 THM 会减少。如果存在游离氯，THMs 会在各种食品的制备和烹饪过程中形成，我们的结果表明，茶可能是 THMs 暴露的一个重要来源。
