Four years ago, the state of Michigan analyzed over 2,000 fish filets across the state for per-and poly fluoroalkyl substances, (PFAS). Although there are more than 16,000 individual PFAS compounds known to exist, one variety, Per Fluoro Octane Sulfonate, (PFOS), made up 82% of the total PFAS in all of the fish tested.
PFOS usage and pathways to human ingestion
PFOS is used in firefighting foam, cookware, carpets, upholstered furniture, and chrome plating, to name a few of the many hundreds of applications. Products containing the toxins are sent down the drain to wastewater treatment plants. They are also buried in landfills, and they are incinerated. None of these methods of disposal destroy the chemical bond of carbon and fluorine that holds PFOS together. The carcinogen is simply recycled. This is what is meant when we call the “forever chemicals.” They never go away.
Wastewater treatment plants typically do not treat PFAS chemicals. The carcinogens are discharged into the rivers, and they contaminate the sewer sludge which is often spread on agricultural fields. This way our fish, produce, and livestock are contaminated. When PFAS is landfilled, the liquid leachate contaminates groundwater and surface water. When PFAS is incinerated the fires often don’t get hot enough so the process results in the chemicals being spread downwind, entering the soil, groundwater, and surface water.
Our fish are contaminated
The average fish in Michigan was found to contain 80,000 parts per trillion of PFOS. (parts per trillion – ppt.) A fish in Oscoda, Michigan near a contamination site contained nearly 10 million ppt of the carcinogenic substance. When the Michigan Department of Environment, Great Lakes, and Energy published these stunning results few took notice, aside from the state’s public radio station.
Few understand the nature and severity of the threat posed by PFOS in the fish while the federal government and the states have downplayed the risk. PFOS is a grave threat to human health that is generally not regulated in the fish that people consume, especially self-caught fish from local waters, both fresh and salt.
The EPA regulates PFOS in drinking water at 4 ppt but does not regulate PFOS in fish, or any food. The average fish in Michigan is 20,000 times over the drinking water limit.
Same problem in Maryland (and everywhere else)
Fishing in the Potomac River at the Piscataway National Park, across from George Washington’s Mount Vernon, where fish are loaded with the carcinogens. “We fry it up.” Photo by Pat Elder
Maryland’s Department of the Environment reported that a largemouth bass, caught at the mouth of Piscataway Creek where it meets the Potomac River, contained 94,200 parts per trillion of PFOS in its filet. See MDE Table 6. That’s a little more than the Michigan average of 80,000 parts per trillion of PFOS in fish.
Maryland says there’s no threat to adults and pregnant women who limit their consumption of largemouth bass in the Potomac to three 8-ounce servings per month. Meanwhile, the state is taking steps to limit PFOS in its drinking water to 4 parts per trillion daily, a tiny fraction of the levels allowed in the fish.
These carcinogens are absorbed by the mother through consumption of the fish and subsequently by the unborn baby via the placenta. Exposure to the family of chemicals that includes PFOS may cause birth defects, premature deliveries, stillbirths, and problems with the nervous system development. Multiple studies have documented PFOS and PFOA levels in the breastmilk of American women to be more than a hundred times higher than the 4 ppt threshold for the chemicals in drinking water.
More on the fish in Maryland
During a December 7, 2023 webinar with John Backus, Program Manager at the Maryland Department of the Environment, was asked about the high levels of PFOS allowed in fish compared to the limit of 4 parts per trillion being mulled by the EPA in drinking water at the time. The Maryland official replied, “It’s important to note that the maximum contaminant level is for drinking water, and it is totally not related but it’s still important in informing the state what our PFAS burden is. So, that criteria obviously could change. You know, there’s been some proposals by EPA that have a different drinking water number. It’s different. It is as simple as that.”
I asked Linda Birnbaum, the former Director of the National Institute of Environmental Health Sciences if this sounded right. She didn’t think so. "Oral is oral," she explained. “Both are routes of ingestion. Whether you eat it or drink it, PFAS go to the same places in the body and do the same thing. We need appropriate fish advisories and regulations,” she said.
Carcinogenic PFAS foam gathers on my beach in Maryland directly across from a known source of contamination. Tests showed the foam contained 3,661 parts per trillion of PFOS. - Photo by Pat Elder
Carcinogenic PFAS foam gathers on my beach in Maryland directly across from a known source of contamination. Tests showed the foam contained 3,661 parts per trillion of PFOS. - Photo by Pat Elder