New data shows that rainwater in some parts of the U.S. contains levels of per- and polyfluoroalkyl substances (PFAS) high enough to impact human health.
New data shows that rainwater in some parts of the U.S. contains high enough levels of potentially toxic per- and polyfluoroalkyl substances (PFAS) to possibly affect human health.
So far, federal regulations usually target only two PFAS variants, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), which are known to cause serious health issues. There are an estimated 4,700 variants total, however.
“There were folks not too long ago who felt the atmospheric transport route was not too important,” said Martin Shafer, principal researcher with the National Atmospheric Deposition Program (NADP). “The data belies that statement.”
Shafer and other researchers came to this conclusion after looking at 37 rainwater samples taken over a week from 30 different sites predominantly near the east coast, reported the Guardian. They found that each sample contained at least one of the 36 different compounds being studied.
"There's a dearth of knowledge about what's supporting the atmospheric concentrations and ultimately deposition of PFAS" said Shaefer.
The total PFAS concentrations were typically less than 1 nanogram per liter and the highest total concentration was nearly 5.5 nanograms per liter in a single sample from Massachusetts, according to the Guardian. Several other samples contained total PFAS levels at about 4 nanograms per liter.
Linda Birnbaum, former director of the National Institute of Environmental Health Sciences, told the Guardian that more research is needed on rainwater and PFAS.
"We see effects on liver, kidney, development, pregnancy, heart," said Birnbaum to NBC News. "I think that's where many people are frustrated. Where there's pretty much growing, and I'd say fairly clear evidence of harm, EPA doesn't have the flexibility to move rapidly."