A new study is raising concerns about contaminants in U.S. drinking water. The study, released by the nonprofit Environmental Working Group, says that American tap water contains contaminates that could lead to nearly 100,000 cases of cancer among people who drink it for a lifetime. Certain communities, including those who rely on small groundwater systems or live in dry climates, appear to have the highest risk.
For the study, the researchers looked at 22 cancer-causing chemicals that were found in US drinking water from 2010 to 2017. The chemicals were divided into three groups: arsenic, radioactive contaminants, and disinfection byproducts. Chemicals were excluded if public water systems hadn’t extensively monitored them or if a government agency hadn’t linked them to cancer. The researchers also excluded drinking water that came from private wells, which the EPA doesn’t monitor.
Overall, the researchers reviewed data that covered approximately 279 million people served by public water systems, which accounts for about 86 percent of the U.S. population. From this data, they predicted that four out of every 10,000 people who drink contaminated water for life could develop cancer as a result. They also found that small groundwater systems have the highest risk of contamination.
Arsenic, which occurs naturally in the Earth’s crust, was identified as a contaminant that could lead to 45,000 cases of cancer. Disinfection byproducts accounted for another 45,000 cancer cases predicted by the researchers. Radioactive contaminants, including radium and uranium, accounted for about 4,500 cases, while the remaining cases were associated with chemicals present in much smaller amounts.
Exposure to multiple contaminants over time can have a cumulative effect on your health. To reduce the risk of negative health effects from contaminated water, it is recommended that you find out where your water comes from, then purchase a filter that’s designed to remove the contaminants in your local system. Switching to bottled water is not recommended, as many bottled water brands are simply repackaged tap water.