Skip to main content

Do Not Eat the Fish

Image placeholder title

Seafood often contains high levels of toxic PFAS. Maryland - What’s in your fish?

PFAS (per- and poly fluoroalkyl substances) used in firefighting foams on military installations in the Chesapeake Bay watershed have contaminated the seafood taken from these waters. The toxic foams have been allowed to seep into the ground and surface water to poison aquatic life.

One variety of PFAS, known as PFOS (Perfluoro Octane Sulfonic Acid) present in firefighting foams, is arguably the most toxic of all 6,000 or so PFAS chemicals on the market. PFOS is linked to a host of cancers, fetal abnormalities, and childhood diseases. PFOS is bioaccumulative in fish and other seafood. Just one part per trillion in the bay and her tributaries is enough to trigger a bioaccumulative process in seafood that is a danger to human health.

PFAS foam gathers on a beach in Southern Maryland

PFAS foam gathers on a beach in Southern Maryland

There are numerous military bases in the region that use these foams, including: Aberdeen Proving Ground, U.S. Naval Academy, Fort George Meade, Naval Research Lab Chesapeake Beach, Patuxent River Naval Air Station, Outlying Webster Field, Indian Head Surface Warfare Center, and Joint Base Andrews.

High concentrations of these chemicals have been discarded by the military into groundwater and surface water that wash into the Chesapeake. The Naval Research Laboratory Chesapeake Bay Detachment in Chesapeake Beach was found to have dumped concentrations of PFAS as high as 241,000 parts per trillion (ppt) into the groundwater on the shore of the Chesapeake. PFOS is extraordinarily mobile in aquifers and surface waters and may travel for many miles. Public health scientists tell us that consuming 1 ppt of these substances in drinking water can be threatening to health.

There is great urgency to focus on human health, particularly the health of women who may be pregnant.

In the absence of EPA regulations, we can look to the European Food Safety Authority (EFSA) for guidance. They estimate that fish and other seafood account for up to 86% of dietary PFAS exposure in adults, yet only 11 U.S. states have enacted fish advisories to warn the public, and these advisories are too high to protect public health.

PFAS continue to contaminate groundwater and surface water on military bases throughout the Chesapeake Bay watershed. 

Graphic - Wisconsin Department of Natural Resources Wisconsin is more proactive than Maryland in gathering data on PFAS contamination of surface water and aquatic life. The state has established fish advisories for the substances, unlike Maryland and most other states.

PFAS Bioaccumulation

Graphic - Wisconsin Department of Natural Resources Wisconsin is more proactive than Maryland in gathering data on PFAS contamination of surface water and aquatic life. The state has established fish advisories for the substances, unlike Maryland and most other states.

Graphic - Wisconsin Department of Natural Resources Wisconsin is more proactive than Maryland in gathering data on PFAS contamination of surface water and aquatic life. The state has established fish advisories for the substances, unlike Maryland and most other states.

Bioaccumulation is the increase in the concentration of a contaminant in an animal over time. PFAS chemicals tend to hang around forever, so even when military bases and industrial sites eventually stop using PFAS, the chemicals remain in the ground, water and/or wildlife. PFAS chemicals are strengthened by their molecular structure of tightly bound carbon and fluoride atoms. It is one of the strongest bonds in the chemical world. These chemicals repel grease, water, and extinguish super-hot petroleum fires better than anything ever developed. Accordingly, the military and industrial applications have been vast and popular.

PFAS doesn’t go away. It bioaccumulates and it sickens people, including the unborn, and wildlife. People shouldn’t eat deer and other game taken near military installations.

Fish consume PFAS from the diet and through the gills. The older the fish, generally, the more PFAS it contains - and the same generally holds true for oysters and crabs.

starkwater-baf-2 450

Bioaccumulation factors are calculated as the ratio of the concentration of PFAS in fish tissue to its concentration in the ambient water. PFOS is thought to be the most bioaccumulative of all PFAS chemicals.

Bioaccumulation factors account for some fish near military bases and industrial sites around the country containing several million parts per trillion of PFOS chemicals, although the waters only contain a tiny fraction of the concentration of the chemicals.

​The Wisconsin Department of Natural Resources found that a fish caught in Starkweather Creek near the Truax Air National Guard Base contained 92.3 parts per billion (ppb) of PFOS. (92,300 parts per trillion). At the same time, the water in the creek was analyzed and contained 53.3 parts per trillion, (ppt). The graphic above demonstrates how the bioaccumulative factor (BAF) is computed. In this case, the BAF is 1,733 liters per kilogram, or L/kg.

Throughout the Great Lakes basin, the BAF for PFOS for all fish is 3,418

Of course, there are many, many variables to consider before we apply these numbers in a wholesale fashion. There are differences between the many PFAS compounds, and the number of manufactured PFAS continues to grow. Fish move around in waters so their travel patterns are thought to affect levels of PFAS concentrations. There are differences in BAF’s from species to species.

Maryland and most other states have not begun to test fish for PFAS.

Data from the U.S. Geological Survey (USGS) Fish Health Research Laboratory sampling project on Antietam Creek, Maryland in 2018 found blood samples in a Smallmouth Bass totaling 574 ppb of several types of PFAS. That’s 574.000 ppt. The fish was taken at the USGS gauge station near the historic Burnside Bridge in the Antietam National Battlefield.

A water sample taken at the same location by the Upper Potomac Riverkeeper found 13.38 ppt of a variety of PFAS chemicals, including 2.7 ppt of PFOS. (Another water sample was collected about three miles upstream at the Hagerstown Wastewater Treatment Plant that contained a total of 138.8 ppt of PFAS, which included 24 ppt of PFOS.)

Image placeholder title
Scroll to Continue

Recommended Articles

If we use the Bioaccumulation formula using 574 ppb/13.38 ppt x 1,000 we arrive at a staggering BAF of 42,900.

PFAS levels in fish are extremely high in locations impacted by major industrial or military PFAS contamination around the country. (e.g. Minnesota Upper Mississippi River, up to 2,000,000 ppt, Delinsky et al., 2010; Decatur, AL, average PFOS – 806,000 ppt, USEPA, 2013; Wurtsmith AFB, MI, PFOS – 9,580,000 ppt, MDHHS, 2015; Barksdale AFB, LA, PFOS – 9,349,000 ppt, Lanza et al., 2017.

The Wisconsin Department of Natural Resources says that surface water levels throughout the state that exceed 2 ppt pose a threat to human health. The truth is that any levels of PFAS are dangerous. Dover AFB, 2013. Overhead suppression systems fitted with PFAS-laden foams were regularly tested and often malfunctioned. One teaspoon of this carcinogenic foam could poison a city’s reservoir. A single drop or two of the chemicals in an Olympic-sized pool could render the water unsafe to drink.
​The Maryland Department of the Environment released data in October, 2020 showing surface water in the St. Mary’s River contained 13.45 ng/l  of PFAS contamination, nearly 7 times higher than the Wisconsin advisory of 2 ng/l. The St. Mary’s River has more than a hundred times the pollution of the .13 ng/l limit established by the European Union. More importantly, the high levels of toxins in the water ensure that all aquatic life are saturated with the toxins.

We ought to know how much PFAS is in this food before we eat it.

We ought to know how much PFAS is in this food before we eat it.

The primary way people are exposed to PFAS is not through drinking water, but through the consumption of seafood. 

Take a look at the attached spreadsheet, PFAS in Seafood. Click on the tab below labelled “PFAS measurements in seafood.” Some of the levels of PFAS in fish that people regularly consume are astronomical. This is a public health crisis.

Here’s a snapshot of the data which pertains only to PFOS. The levels are shown in parts per trillion. Many states are limiting the consumption of PFAS to under 20 parts per trillion in drinking water. 

Location State Species Units Chemical

Miss. River near Wabasha MN,WI Sauger 237,000 PFOS
Missouri Riv. Below Omaha NE, IA Shad 394,000 PFOS
Missouri Riv. north of K.C. KS, MO Shad 225,000 PFOS
Missouri Riv. S. of Jeff. City MO Drum 532,000 PFOS
Ohio River below Parkersburg OH, WV White Bass 354,000 PFOS
Ohio River near its source PA Redhorse 489,000 PFOS
Ohio River, New Martinsville OH, WV Shad 267,000 PFOS
Ohio River south of Paducah KY, IL Threadfin 1,250,000 PFOS


There is no standard between government bodies and no reasoning provided as to why some states are promulgating regulations limiting PFAS in drinking water at levels under 20 parts per trillion, while other states are not. Further, as PFAS are known toxic compounds, it makes little sense why drinking water is regulated while the public is free to consume crustaceans and fish that may contain more of the toxins in a single seafood platter than drinking water containing 20 ppt every day during an 80-year lifetime.

Certainly, the military is not the cause of all of this contamination. The responsibility is shared with industrial polluters and state regulators who are not paying attention.

EPA Staff in the Midwest compiled the following data related to PFOS values:

State PFOS Fish Tissue Advisory Values, Compiled June 2020

Image placeholder title

*High risk or sensitive populations are considered to be at higher risk from contaminants in fish than members of the general public. This group includes infants, children, pregnant women, nursing mothers and women of childbearing age.
** GLC is Great Lakes Consortium for Fish Consumption Advisories (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin, the Ministry of the Environment, Conservation and Parks of Ontario, Canada, and the Great Lakes Indian Fish and Wildlife Commission)

39 states have still not begun to regulate PFAS consumption in seafood. The 11 that have started to regulate the dangerous substance have established levels that are thousands - and even tens of thousands of times higher than the levels of PFAS tolerated in drinking water in many states. For instance, New Jersey limits PFOS to 13 ppt in drinking water, yet Alabama will allow residents to consume fish containing up to 800,000 ppt. of the stuff.

It’s like that in the absence of a federal presence. Congress doesn’t think its important, but they will, once the public understands the threat. The 11 states listed in the table above have used an 8-ounce (227 g) meal size when calculating PFOS advisory values for adults. It’s somewhat unrealistic, considering the portions served to an increasingly obese American public. Advisory values for PFOS concentrations in fish tissue given in this table are for the 1 meal/week consumption frequency.

These limits are in parts per billion, so we must multiply by a thousand to be on the same polyfluoroalkyl page with PFAS maximum contaminant levels (MCL’s) set by several states for drinking water.

There are several hot spots for PFAS contamination in the rivers in these states. For instance, Oregon, which has instituted a 200,000 ppt limit, is the home of the Portland Air National Guard Base located on the Columbia River. The base has contaminated the groundwater with 31,800 ppt of the two deadliest types of PFAS and it all empties into the Columbia. It’s like a tsunami of carcinogens while people are free to eat the fish.DLA keeps track of this stuff. They know the score.

Where is it coming from?

Locating military installations that are contaminating groundwater, creeks, rivers, and the ocean is relatively easy to do, using Navy and Air Force search sites. The Army is not as transparent.

Earth Justice has provided us with the locations of nine sites in the US where PFAS is slated to be incinerated by contractors working with the Defense Logistics Agency, (DLA). PFAS may remain intact after being incinerated, so surface water downwind of these plants may be contaminated. The DLA’s Qualified Facilities List is also a good place to examine potential locations for PFAS use and disposal across the country.

Identifying industrial polluters of PFAS isn’t too tough, either. For starters, simply search for PTFE Coatings Suppliers to come up with an abbreviated list of companies that may be contaminating waterways with these chemicals. Manufacturing processes involving PFAS cause problems, period.

pat elder 2019

​Maryland and other states asleep at the PFAS switch should be testing their waters and their fish and they ought to be warning the public not to consume seafood without knowing what’s in it.

​PFAS is a serious danger to the developing fetus. 

Pat Elder