At least two-thirds of drinking water in the United States contains uranium, according to a new study from Columbia University’s Mailman School of Public Health.
The research, which was focused on metal concentrations in U.S. community water systems (CWS), also revealed patterns of inequalities. The highest levels of uranium, selenium, barium, chromium, and arsenic were found in Hispanic communities, which raises environmental justice concerns.
Uranium, in particular, is a known risk factor for the development of chronic diseases, even at low levels.
“Previous studies have found associations between chronic uranium exposure and increased risk of hypertension, cardiovascular disease, kidney damage, and lung cancer at high levels of exposure,” said Dr. Anne Nigra.
“Our objectives were to estimate CWS metal concentrations across the U.S, and identify sociodemographic subgroups served by these systems that either reported high metal concentration estimates or were more likely to report averages exceeding the US EPA’s maximum contaminant level (MCL).”
In the United States, around 90 percent of residents rely on public drinking water systems. Most residents rely specifically on community water systems that serve the same population year-round, noted the researchers.
For the investigation, the experts analyzed EPA review records from 139,000 public water systems serving 290 million people
The goal was to determine if average concentrations of antimony, arsenic, barium, beryllium, cadmium, chromium, mercury, selenium, thallium, and uranium exceeded the “safe” contaminant levels established by the EPA.
The study revealed that during compliance monitoring, uranium was detected in community water systems 63 percent of the time.
The researchers noted that the consistent association between elevated CWS metal concentrations and semi-urban, Hispanic communities implies that concentration disparities are a failure of regulatory policy or treatment rather than underlying geology.
“Additional regulatory policies, compliance enforcement, and improved infrastructure are therefore necessary to reduce disparities in CWS metal concentrations and protect communities served by public water systems with elevated metal concentrations,” said Dr. Nigra.
“Such interventions and policies should specifically protect the most highly exposed communities to advance environmental justice and protect public health.”
The study was supported by the US National Institutes for Environmental Health Sciences. The results are published in the journal The Lancet Planetary Health.
By Chrissy Sexton, Earth.com Staff Writer