Well water linked to bladder cancer

*Researchers believe arsenic exposure might contribute to higher-than-normal rates

Arsenic in drinking water from private wells may explain the elevated bladder cancer risk among people in three New England states, a new study suggests.

Bladder cancer rates in Maine, New Hampshire and Vermont have been about 20 percent higher than the national rate for more than 50 years, the researchers noted. They said this difference was not explained by factors such as smoking or job exposures.

The study findings were published in the Journal of the National Cancer Institute.

Chief of the Occupational and Environmental Epidemiology Branch of the United States (U.S.) National Cancer Institute and senior study author, Debra Silverman, said: “Arsenic is an established cause of bladder cancer, largely based on observations from earlier studies in highly exposed populations,” said

“However, emerging evidence suggests that low to moderate levels of exposure may also increase risk.”

Many people in these states have private wells, which are not maintained by municipalities and are not subject to federal regulations, the researchers said.

These wells may contain arsenic, typically at low to moderate levels. Previous research has shown that drinking water with high levels of arsenic increases the risk of bladder cancer, the study team said. Possible sources of arsenic in the wells include natural release from rock deep in the ground and pesticides widely used on crops between the 1920s and 1950s, according to the study.

For the study, the researchers compared more than 1,200 newly diagnosed bladder cancer patients with more than 1,400 people without bladder cancer who lived in the same areas.