Bates Michael N, Rey Omar A, Biggs Mary L, Hopenhayn Claudia, Moore Lee E, Kalman David, Steinmaus Craig, Smith Allan H
Arsenic Health Effects Research Group, School of Public Health, University of California, Berkeley, CA 94720-7360, USA.
Am J Epidemiol. 2004 Feb 15;159(4):381-9. doi: 10.1093/aje/kwh054.
Studies have found increased bladder cancer risks associated with high levels of arsenic in drinking water, but little information exists about risks at lower concentrations. Ecologic studies in Argentina have found increased bladder cancer mortality in Córdoba Province, where some wells are contaminated with moderate arsenic concentrations. This population-based bladder cancer case-control study in two Córdoba counties recruited 114 case-control pairs, matched on age, sex, and county, during 1996-2000. Water samples, particularly from wells, were obtained from subjects' current residences and residences in the last 40 years. Statistical analyses showed no evidence of associations with exposure estimates based on arsenic concentrations in drinking water. However, when well-water consumption per se was used as the exposure measure, time-window analyses suggested that use of well water more than 50 years before interview was associated with increased bladder cancer risk. This association was limited to ever smokers (odds ratio = 2.5, 95% confidence interval: 1.1, 5.5 for 51-70 years before interview), and the possibility that this association is due to chance cannot be excluded. This study suggests lower bladder cancer risks for arsenic than predicted from other studies but adds to evidence that the latency for arsenic-induced bladder cancers may be longer than previously thought.
研究发现，饮用水中高含量的砷会增加患膀胱癌的风险，但关于较低浓度砷的风险信息却很少。阿根廷的生态学研究发现，科尔多瓦省的膀胱癌死亡率有所上升，该省一些水井被中等浓度的砷污染。这项在科尔多瓦省两个县开展的基于人群的膀胱癌病例对照研究，在1996年至2000年期间招募了114对病例对照，根据年龄、性别和所在县进行匹配。从研究对象当前的住所以及过去40年居住过的住所采集水样，尤其是来自水井的水样。统计分析表明，没有证据显示与基于饮用水中砷浓度的暴露估计值存在关联。然而，当将井水本身的使用情况作为暴露衡量指标时，时间窗分析表明，在访谈前50多年使用井水与膀胱癌风险增加有关。这种关联仅限于曾经吸烟者（比值比 = 2.5，95%置信区间：访谈前51 - 70年为1.1，5.5），且不能排除这种关联是由偶然因素导致的可能性。这项研究表明，砷导致的膀胱癌风险低于其他研究预测的风险，但进一步证明了砷诱发膀胱癌的潜伏期可能比之前认为的更长。
