Graduate Program in Public Health, Department of Preventive Medicine, Stony Brook University Medical Center, Stony Brook, NY 11794-8338, USA.
Cancer Causes Control. 2010 May;21(5):745-57. doi: 10.1007/s10552-010-9503-z. Epub 2010 Jan 19.
Arsenic in drinking water has been linked with the risk of urinary bladder cancer, but the dose-response relationships for arsenic exposures below 100 microg/L remain equivocal. We conducted a population-based case-control study in southeastern Michigan, USA, where approximately 230,000 people were exposed to arsenic concentrations between 10 and 100 microg/L.
This study included 411 bladder cancer cases diagnosed between 2000 and 2004, and 566 controls recruited during the same period. Individual lifetime exposure profiles were reconstructed, and residential water source histories, water consumption practices, and water arsenic measurements or modeled estimates were determined at all residences. Arsenic exposure was estimated for 99% of participants' person-years.
Overall, an increase in bladder cancer risk was not found for time-weighted average lifetime arsenic exposure >10 microg/L when compared with a reference group exposed to <1 microg/L (odds ratio (OR) = 1.10; 95% confidence interval (CI): 0.65, 1.86). Among ever-smokers, risks from arsenic exposure >10 microg/L were similarly not elevated when compared to the reference group (OR = 0.94; 95% CI: 0.50, 1.78).
We did not find persuasive evidence of an association between low-level arsenic exposure and bladder cancer. Selecting the appropriate exposure metric needs to be thoughtfully considered when investigating risk from low-level arsenic exposure.
饮用水中的砷已被证实与膀胱癌的发病风险相关,但在 100μg/L 以下的砷暴露剂量-反应关系仍存在争议。我们在美国密歇根州东南部进行了一项基于人群的病例对照研究,该地区约有 23 万人暴露于 10-100μg/L 的砷浓度中。
该研究纳入了 2000 年至 2004 年间诊断出的 411 例膀胱癌病例和同期招募的 566 例对照。对个体的终生暴露情况进行了重建,并确定了所有住所的饮用水源史、水摄入量、以及水中砷含量的测量值或模型估算值。99%的参与者的个人暴露年限都进行了砷暴露评估。
总体而言,与接触<1μg/L 的参考组相比,当将 >10μg/L 的时间加权平均终生砷暴露值与膀胱癌风险进行比较时,并未发现膀胱癌风险增加(比值比(OR)=1.10;95%置信区间(CI):0.65,1.86)。在所有吸烟者中,与接触<1μg/L 的参考组相比,>10μg/L 的砷暴露风险也没有升高(OR=0.94;95%CI:0.50,1.78)。
我们没有发现低水平砷暴露与膀胱癌之间存在关联的有力证据。在调查低水平砷暴露风险时,需要慎重考虑选择适当的暴露度量标准。