In recent years, the scientific community has raised alarms about the prevalence of PFAS—or “forever chemicals—on the landscape. According to the EPA, the chemical compounds, which are used in everything from household products to industrial treatments, break down slowly and are “widespread and persistent in the environment.” They’re also linked to harmful health impacts to humans and animals.
Migratory waterfowl have been impacted by PFAS, too, triggering local consumption advisories in areas with high PFAS concentrations. For instance, the Wisconsin DNR issued a consumption advisory for ducks harvested on Green Bay in September. The most glaring issue involving PFAS-contaminated waterfowl—so far—occurred in New Mexico, where researchers found record-breaking concentrations of PFAS in birds and small mammals near Holloman Lake—a popular waterfowl hunting area in Southern New Mexico. The news prompted health officials to urge local hunters to contact their doctors if they consumed birds from the waterbody, and to stop hunting there.
The incident put a spotlight on PFAS contamination in waterfowl. But what does the average waterfowl hunter need to know about it? We recently spoke with Christopher Witt, a Professor of Biology at the University of New Mexico and a leading researcher on the Holloman Lake case, to find out.
Whitt, an avid hunter himself, actually used duck hunting to collect birds from Holloman Lake, which was already a known hotspot for PFAS contamination because of the nearby use of flame retardants by the Air Force. However, the impact on local wildlife wasn’t fully understood.
“The results were totally shocking,” he says. “The contamination was several orders of magnitudes higher than what’s considered safe for human consumption.”
Unfortunately, this likely wouldn’t have been immediately apparent to hunters; while some of the birds sampled appeared sick, many of them did not. This points to a critical lack of understanding: scientists don’t know much about how PFAS contamination impacts the behavior of migratory waterfowl. Right now, Whitt and his colleagues are working with small rodents to study behavioral impacts.
“There are lots of reasons to think that high levels of PFAS are really harmful to ducks and other water birds,” he says. “But it’s difficult to document that in the wild.”
The impact on humans is better understood, and high PFAS levels can lead to a plethora of health concerns, including cancer, liver disease, thyroid disease, poor birth outcomes for pregnant women, and more.
While it may be simple to avoid ducks by not hunting known PFAS hotspots, migratory birds are, well, migratory. Witt says his team has been looking at bird samples in the general vicinity of Holloman Lake. So far, there’s reason for worry—and optimism.
“We found there was a decisive difference in birds at other wetlands,” he says. “They were generally not contaminated, but they did have trace levels of PFAS, including some compounds that weren’t found at Holloman Lake. This suggests that ducks are picking up different types of contamination as they fly around.”
The good news is that those ducks with trace levels of contamination are relatively safe for human consumption. Additionally, companies have significantly phased out PFAS over the last two decades, and because of this, PFAS on the landscape is trending down.
As for Witt, himself, he still hunts and eats ducks, with one caveat. “I myself would not eat duck livers anymore,” he says. “The livers concentrate those toxins at higher levels, and that risk just doesn’t make sense to me.”
Ultimately, Witt says that the average bird hunter shouldn’t worry about PFAS contamination—but they should be informed. “It’s important to check media coverage in your region and find out what PFAS contamination concerns there are in your region,” he says. In some areas, there are concerns about PFAS-contaminated sewage on farm fields. In other areas, there are known contamination sources in waterways that you might want to avoid.”
Witt adds that research will continue to further elucidate the threats of PFAS to waterfowl and waterfowl hunters. “[Duck hunters] need to be vigilant and vocal in the community that’s making sure that we don’t allow this kind of contamination of game to happen,” he says. “It’s a difficult problem to conceptualize because it’s an invisible one. But these manmade chemicals have all sorts of potential dangers.”