Arsenic Health Effects Research Group, School of Public Health, University of California, Berkeley, CA.
Departamento de Estadística, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago, Chile.
J Natl Cancer Inst. 2018 Mar 1;110(3):241-249. doi: 10.1093/jnci/djx201.
Region II in northern Chile (population 442 570) experienced a sudden major increase in arsenic water concentrations in 1958 in the main city of Antofagasta, followed by a major reduction in exposure when an arsenic removal plant was installed in 1970. It provides a unique opportunity to study latency effects of exposure to arsenic, and this is the first study with mortality data up to 40 years after exposure reduction.
We previously identified high mortality rates in Region II up to the year 2000. Here we present rate ratios (RRs) for Region II compared with all the rest of Chile from 2001 to 2010, and with unexposed Region V (population 1 539 852) for all years from 1950 to 2010. All statistical tests were one-sided.
From 2001 to 2010, comparing Region II with the rest of Chile, lung and bladder mortality were still greatly elevated (RR = 3.38, 95% confidence interval [CI] = 3.19 to 3.58, P < .001 for lung cancer in men; RR = 2.41, 95% CI = 2.20 to 2.64, P < .001 for lung cancer in women; RR = 4.79, 95% CI = 4.20 to 5.46, P < .001 for bladder cancer in men; RR = 6.43, 95% CI = 5.49 to 7.54, P < .001 for bladder cancer in women). Kidney cancer mortality was also elevated (RR = 1.75, 95% CI = 1.49 to 2.05, P < .001 for men; RR = 2.09, 95% CI = 1.69 to 2.57, P < .001 for women). Earlier short latency acute myocardial infarction mortality increases had subsided.
Lung, bladder, and kidney cancer mortality due to arsenic exposure have very long latencies, with increased risks manifesting 40 years after exposure reduction. Our findings suggest that arsenic in drinking water may involve one of the longest cancer latencies for a human carcinogen.
智利北部第二地区（人口 442570 人）于 1958 年在主要城市安托法加斯塔经历了砷饮用水浓度的突然大幅增加，随后在 1970 年安装了除砷厂后，暴露量大幅减少。这为研究砷暴露的潜伏期效应提供了一个独特的机会，这也是首次在暴露减少 40 年后用死亡率数据进行的研究。
我们之前已经确定了第二地区直到 2000 年的高死亡率。在这里，我们展示了 2001 年至 2010 年与智利其他地区相比的比率（RR），以及 1950 年至 2010 年与未暴露地区 V（人口 1539852 人）相比的比率。所有统计检验均为单侧检验。
从 2001 年到 2010 年，与智利其他地区相比，第二地区的肺癌和膀胱癌死亡率仍然很高（RR=3.38，95%置信区间[CI]为 3.19 至 3.58，P<.001，男性肺癌；RR=2.41，95%CI=2.20 至 2.64，P<.001，女性肺癌；RR=4.79，95%CI=4.20 至 5.46，P<.001，男性膀胱癌；RR=6.43，95%CI=5.49 至 7.54，P<.001，女性膀胱癌）。肾癌死亡率也升高（RR=1.75，95%CI=1.49 至 2.05，P<.001，男性；RR=2.09，95%CI=1.69 至 2.57，P<.001，女性）。先前的短期潜伏期急性心肌梗死死亡率增加已经平息。
由于砷暴露导致的肺癌、膀胱癌和肾癌的死亡率潜伏期非常长，暴露减少 40 年后风险增加。我们的研究结果表明，饮用水中的砷可能涉及人类致癌物中最长的癌症潜伏期之一。
