New research on pollutants in public drinking water has found that exposure to these carcinogenic chemicals could cause thousands of new cancer cases.
In the first study of its kind, researchers from the Environmental Working Group assessed the combined health impacts of 22 carcinogens found in 48,363 community water systems (excluding private well water).
The study was published in the journal Heliyon.
The health impacts of water contaminants are usually evaluated on an individual basis.
For this study, the researchers used a cumulative approach to analyze drinking water and its associated cancer risks, the same kind of method used for measuring the health impacts of air pollution exposure.
“Drinking water contains complex mixtures of contaminants, yet government agencies currently assess the health hazards of tap water pollutants one by one,” said Sydney Evans, the lead author of the paper. “In the real world, people are exposed to combinations of chemicals, so it is important that we start to assess health impacts by looking at the combined effects of multiple pollutants.”
The analysis revealed that carcinogens in US drinking water could cause more than 100,000 cancer cases and increase cancer risk nationwide.
Water systems that rely on groundwater and provide water to smaller communities have the highest risks. Contaminants like arsenic and radioactive elements had the most significant impact on cancer risk.
The majority of water systems in the US meet legal standards for contaminant levels, the researchers note.
However, the results show that exposure to even permissible levels of contaminants results in increased cancer risks.
“We need to prioritize source water protection, to make sure that these contaminants don’t get into the drinking water supplies to begin with,” said Olga Naidenko, a member of the research team.
The researchers recommend that consumers install water filters to limit exposure to pollutants and that filters be tailored for specific contaminants.
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