Arsenic Levels in Drinking Water Tied to Elevated Bladder Cancer Risk

Low-to-moderate levels of arsenic in drinking water were linked to increased risk for bladder cancer and may have contributed to elevated bladder cancer rates in northern New England.¹

For 5 decades, incidence rates of bladder cancer in Maine, New Hampshire, and Vermont have been about 20% higher than in the rest of the United States. Focusing on levels of arsenic found in private wells, which are common in the region, investigators sought to explain these elevated rates of bladder cancer mortality in northern New England.

In this population-based case-control study, investigators looked at 1213 patients with bladder cancer and 1418 control subjects. Participants provided information on suspected risk factors and log transformed arsenic concentrations were estimated by linear regression based on measurements in water samples from current and past residences.

Results showed that bladder cancer risk was linked with increased water intake (P_trend = .003). The link was statistically significant among participants with a history of private well use (P_trend = .01). The trend was more apparent in those with shallow dug wells, which are more prone to surface contamination than deeper drilled wells. Those who drank from wells dug prior to 1960, when arsenical pesticides were widely used, and had heavier water consumption (more than 2.2 L/day) had double the risk of light consumers (less than 1.1 L/day; P_trend = .01).

Reference

1. Baris D, Waddell R, Beane Freeman LE, et al. Elevated bladder cancer in northern New England: the role of drinking water and arsenic. J Natl Cancer Inst. 2016;108(9). doi: 10.1093/jnci/djw099.