CLEVELAND, OH — Rain that fell on Ohio this spring contained a surprisingly high amount of toxic “forever chemicals” known as PFAS, according to raw data from a binational Great Lakes monitoring program that tracks airborne pollution.
Rainwater collected in Cleveland over two weeks in April contained a combined concentration of about 1,000 parts-per-trillion (ppt) of PFAS compounds. That’s according to scientists at the Integrated Atmospheric Deposition Network (IADN), a long-term Great Lakes monitoring program jointly funded by the U.S. Environmental Protection Agency and Canada.
The samples are part of a new IADN effort to analyze the prevalence of PFAS in precipitation across the Great Lakes. The network has other monitoring stations in Illinois, Michigan and New York and the chemicals were detected there, too.
The preliminary data is unpublished and undergoing quality reviews, but researchers say early analysis shows PFAS chemicals to be major contaminant in regional rain and snow.
“You can actually say it’s raining PFAS at this point,” said Marta Venier, an environmental chemist Indiana University, speaking to reporters convened online by the Institute for Journalism and Natural Resources (IJNR) in May.
Since August 2020, IADN has been analyzing PFAS in rainwater samples from five sites around the region where the IADN has, since 1990, been testing for persistent organic pollutants like PCBs, organochlorine pesticides and flame retardants.
The sites are located in Cleveland, Chicago, Sturgeon Point, N.Y., Sleeping Bear Dunes in Michigan’s northern Lower Peninsula and Eagle Harbor in the Upper Peninsula.
The team measured 38 different PFAS compounds in ambient air and rainwater. The total concentration in most samples ranged from 100 to about 400-ppt across the sites, with higher counts at urban compared to rural or remote sites.
After nearly a year’s worth of sampling, Venier said preliminary analysis also shows PFAS concentrations are orders of magnitude higher than other pollutants in the samples.
Many of the PFAS chemicals in the samples are so-called “short chain” replacement compounds that have been favored by manufacturers in recent years as an alternative to earlier variations with longer chemical chains, such as PFOS and PFOA, which were phased out under regulatory pressure in the United States but are still manufactured overseas.
The samples show significant quantities of 6:2, 8:2, and 10:2 FTCAs, or fluorotelomer carboxylic acids often used in industrial settings or as grease-proofing agents on food contact paper.
“It’s clearly reflective of the transition from long-chain to short-chain,” Venier told MLive. “Those are fairly abundant in these samples and those are also the ones that we see a lot in consumer products.”
Venier said people don’t need to worry about becoming stain-resistant after being out in the rain. The primary concern is still exposure through ingestion or contact with PFAS-coated products, but the contaminated precipitation does, nonetheless, spread the robust chemicals around the environment where they build-up in water bodies and wildlife.
Spread through atmospheric deposition is also likely contributing to a manmade “background” level of the contaminants within the environment, she said.
“They accumulate,” she said. “Once they are out there, they really stay out there. All of this is to say it’s not an immediate concern for a person, but it is a concern long-term for the environment because they keep raining out.”
The IADN research was previewed last month by graduate student Abby DeMeyer during the International Association for Great Lakes Research (IAGLR) annual conference. DeMeyer said the team plans to study seasonal trends in concentrations as their raw data collection increases.
There is still much to be learned about long-range movement of PFAS through the atmosphere, but the IADN effort adds to a growing body of research on the atmospheric movement and deposition of the chemicals.
In April, researchers with the College of Wooster detected 17 different kinds of PFAS in the summer of 2019 at seven urban, suburban and rural sample sites in Ohio and Indiana, with total concentrations ranging from 50 to 850-ppt.
Similar research conducted primarily along the east coast in 2019 by the University of Wisconsin-Madison-based National Atmospheric Deposition Program (NADP) found lower concentrations, mostly in the single-digit ppt range.
In North Carolina, state investigators traced GenX variations of the chemistry in rainwater to Chemours chemical manufacturing emission. The concentrations measured in 2018 reached 630-ppt in some samples and prompted the state environmental agency — lead at the time by Michael Regan, now head of the EPA — to order emission reductions.
“These findings lend weight to our belief that airborne GenX contributes to contamination of private wells and lakes near Chemours’ facility,” Regan said at the time.
Abby Hendershott, director of the Michigan PFAS Action Response Team (MPART) at the state Department of Environment, Great Lakes and Energy (EGLE), said the preliminary IADN results seem “pretty high” based on what she’s heard about PFAS in rainwater.
Hendershott leads a regulatory program that investigates PFAS sites in Michigan and collects data on the chemicals in drinking water, soil, wastewater and other environment media.
Since the MPART program began in 2017, the state has struggled at times to explain PFAS detections in some areas, such as in groundwater wells upgradient from a known source, or low-level concentrations in water bodies lacking an obvious source for the contaminants.
“We keep finding trace levels of PFAS around the state, which says something about its ubiquitous nature and the fact it must be able to travel through the air,” she said.
Tony Spaniola, a national PFAS activist and attorney who owns a home near the former Wurtsmith Air Force Base in Oscoda, Mich., was surprised to see significant concentrations at remote locations like Sleeping Bear Dunes and Eagle Harbor.
“It isn’t like there’s a smokestack by Sleeping Bear Dunes,” said Spaniola. “Those numbers are nothing to sneeze at. It has to come from some place.”
Spaniola, who works in Troy, wonders about Detroit.
“With all the industry around the Detroit area, particularly Downriver, I bet the numbers there are huge,” he said, particularly around the Marathon oil refinery, where huge amounts “mystery foam” later confirmed to be PFAS began oozing from an old sewer pipe in 2018, causing a closure of Schaefer Highway.
“It’s everywhere,” Spaniola said. “I’m not happy to say that. It’s not good news. But it underscores how ubiquitous these chemicals are. They are everywhere.”
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