In a study on metal concentrations in U.S. community water systems (CWS) and patterns of inequalities, researchers at Columbia University Mailman School of Public Health found that metal concentrations were particularly elevated in CWSs serving semi-urban, Hispanic communities independent of location or region, highlighting environmental justice concerns. These communities had the highest levels of uranium, selenium, barium, chromium, and arsenic concentrations.
Even at low concentrations, uranium represents an important risk factor for the development of chronic diseases. Until now, little epidemiological research had been done on chronic water uranium exposures despite the potential health effects of uranium exposure from CWSs. Uranium, in particular, has been underappreciated in the literature as a public drinking water contaminant of concern. The study results are published in the journal The Lancet Planetary Health.
“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 Anne Nigra, PhD, assistant professor of Environmental Health Sciences at Columbia Mailman School of Public Health. “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 U.S. EPA’s maximum contaminant level.”
Approximately 90 percent of U.S. residents rely on public drinking water systems, with most residents relying specifically on CWSs that serve the same population year-round. The researchers evaluated six-year EPA review records for antimony, arsenic, barium, beryllium, cadmium, chromium, mercury, selenium, thallium, and uranium to determine if average concentrations exceeded the maximum contaminant levels set by the EPA which regulates levels for six classes of contaminants. This included approximately 13 million records from 139,000 public water systems serving 290 million people annually. The researchers developed average metal concentrations for 37,915 CWSs across the country, and created an online interactive map of estimated metal concentrations at the CWS and county levels to use in future analyses.