Institute of Occupational Safety and Health, College of Health Sciences, Kaohsiung Medical University, and Department of Internal Medicine, Yuan's General Hospital, Kaohsiung, Taiwan.
J Toxicol Environ Health A. 2011;74(6):392-403. doi: 10.1080/15287394.2011.538836.
The objectives of this study were to (1) examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and death attributed to colon cancer and (2) determine whether magnesium (Mg) levels in drinking water modify the effects of TTHM on risk of colon cancer development. A matched case-control study was used to investigate the relationship between the risk of death attributed to colon cancer and exposure to total trihalomethanes (TTHM) in drinking water in 53 municipalities in Taiwan. All colon cancer deaths of the 53 municipalities from 1998 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from Taiwan Environmental Protection Administration. Information on the levels of Mg in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM and Mg exposure via drinking water. Relative to individuals whose TTHM exposure levels were <4.9 ppb, the adjusted odds ration (OR) (with 95% confidence interval [CI]) for colon cancer was 1.14 (1.01-1.28) for individuals who had resided in municipalities served by drinking water with a TTHM exposure≥4.9 ppb. Evidence of an interaction between drinking-water TTHM and Mg intake via drinking water was noted. This is the first study to report an effect modification by Mg intake from drinking water in association between TTHM exposure and risk of colon cancer occurrence. Better knowledge of this modifying factor will help in public policymaking and setting health standards.
(1) 检验公共供水系统中总三卤甲烷 (TTHM) 水平与归因于结肠癌的死亡之间的关系；(2) 确定饮用水中镁 (Mg) 水平是否会改变 TTHM 对结肠癌发展风险的影响。本研究采用病例对照研究，调查了台湾 53 个市饮用水中总三卤甲烷（TTHM）暴露与归因于结肠癌的死亡风险之间的关系。所有 53 个市 1998 年至 2007 年归因于结肠癌的死亡均来自台湾省卫生署生命统计处。对照是其他原因导致的死亡，通过性别、出生年份和死亡年份与癌症病例相匹配。每个匹配的对照是从每个癌症病例的可能对照集中随机选择的。饮用水中 TTHM 水平的数据来自台湾环境保护署收集。饮用水中 Mg 水平的信息来自台湾自来水公司。癌症病例和对照的居住市被认为是通过饮用水暴露于 TTHM 和 Mg 的来源。与 TTHM 暴露水平<4.9 ppb 的个体相比，暴露于 TTHM≥4.9 ppb 的饮用水的个体患结肠癌的调整比值比 (OR)（95%置信区间 [CI]）为 1.14（1.01-1.28）。注意到饮用水 TTHM 与通过饮用水摄入 Mg 之间存在交互作用的证据。这是第一项报告饮用水 TTHM 暴露与结肠癌发生风险之间存在 Mg 摄入的交互作用的研究。更好地了解这种调节因素将有助于公共政策制定和健康标准的制定。
