Marienfeld C J, Collins M, Wright H, Reddy R, Shoop G, Rust P
J Environ Pathol Toxicol Oncol. 1986 Sep-Dec;7(1-2):141-57.
St. Louis City and St. Louis County, Missouri share the same public drinking water source, namely the Missouri River. The 'all cancer' and most organ specific cancer mortality rates have been consistently and considerably higher for St. Louis City than for St. Louis County for the period 1960 through 1972. A change in the St. Louis County water treatment process, which included increasing the chlorine dosage and delaying the addition of ammonia to form chloramines until just prior to distribution, was instituted in 1955. St. Louis City has, by contrast, continued the lower chlorine level and early ammoniation. Trend analysis using the period 1960-67 and 1972-76 showed higher percentage as well as net cancer mortality rate per million increases for large bowel, liver and bladder cancers for St. Louis County. An apparent association between a probable increase in trihalomethane production in the St. Louis County water since 1955 and an increase in these specific cancer rates which exceed the increases in the St. Louis City rates appears to have been shown. This does not imply causality but is in general agreement with other studies which have examined water chlorination and cancer mortality.
密苏里州的圣路易斯市和圣路易斯县共用同一公共饮用水源，即密苏里河。在1960年至1972年期间，圣路易斯市的“所有癌症”以及大多数器官特异性癌症死亡率一直且显著高于圣路易斯县。1955年，圣路易斯县对水处理工艺进行了更改，包括增加氯剂量并将添加氨以形成氯胺的时间推迟到临近供水前。相比之下，圣路易斯市一直保持较低的氯含量和早期氨化处理。使用1960 - 67年和1972 - 76年期间进行的趋势分析表明，圣路易斯县的结肠癌、肝癌和膀胱癌每百万新增病例的癌症死亡率百分比以及净死亡率更高。自1955年以来，圣路易斯县水中三卤甲烷产量可能增加与这些特定癌症发病率增加之间存在明显关联，且这些癌症发病率的增加超过了圣路易斯市的增幅。这并不意味着存在因果关系，但总体上与其他研究水氯化与癌症死亡率的研究结果一致。
