Exposure to PFAS may be underestimated

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“Our recommendation isn’t to not eat seafood—seafood is a great source of lean protein and omega fatty acids.
But it also is a potentially underestimated source of PFAS exposure in humans,” says Megan Romano, the study’s corresponding author and an associate professor of epidemiology at the Geisel School of Medicine.
Quote Most existing research focuses on PFAS levels in freshwater species, which are not what people primarily eat.
In humans, PFAS are associated with cancer, fetal abnormalities, high cholesterol, and thyroid, liver, and reproductive disorders.
Concentrations of individual PFAS in other fish and seafood measured generally less than one nanogram per gram.
The survey found that men in New Hampshire eat just over one ounce of seafood per day and women eat just under one ounce.
But people in New Hampshire do not eat seafood uniformly.
“Top predator species such as tuna and sharks are known to contain high concentrations of mercury, so we can use that knowledge to limit exposure.


The family of persistent and widely distributed man-made toxins known as “forever chemicals,” or PFAS, may pose a greater risk to individuals who regularly eat seafood, according to a Dartmouth-led study. “.

According to the researchers’ findings, which are published in the journal Exposure and Health, people should be exposed to fewer perfluoroalkyl and polyfluoroalkyl substances by following stricter public health guidelines that specify how much seafood is safe to eat. According to the authors, this need is particularly critical for coastal areas like New England where a cultural preference for fish coexists with a legacy of industry and PFAS contamination.

Seafood is a fantastic source of lean protein and omega fatty acids, so we don’t advise against eating it. However, Megan Romano, the corresponding author of the study and an associate professor of epidemiology at the Geisel School of Medicine, notes that it is also a potentially underestimated source of PFAS exposure in humans.

Romano asserts that “people making dietary decisions, especially for vulnerable populations like pregnant people and children, need to understand this risk-benefit trade-off for seafood consumption.”.


The majority of current research concentrates on PFAS levels in freshwater species, which do not constitute the majority of human diets. We considered that to be a gap in the literature, particularly concerning a state in New England.

Taking credit.

Megan Romano is an epidemiology associate professor.

Using New Hampshire as a case study, the study examined how much seafood is consumed in New England and other coastal states by combining an analysis of PFAS concentrations in fresh seafood with a state-wide eating habits survey. The state was perfect for determining the amount of PFAS exposure from fish and shellfish because national data show that New Hampshire, along with the entirety of New England, is among the top seafood consumers in the nation.

Romano studies the effects of PFAS and other endocrine-disrupting chemicals in drinking water on communities in New England. “Most existing research focuses on PFAS levels in freshwater species, which are not what people primarily eat,” says Romano. We recognized that as a lacuna in the literature, particularly for a New England state where seafood is well-liked. “.

The investigation also benefited from New Hampshire’s rich data on the origins and consequences of per- and polyfluoroalkyl substances (PFAS), which are ubiquitous in consumer goods like plastics and nonstick coatings. PFAS, also known as “forever chemicals,” are versatile due to their molecular stability, which also makes them nearly unbreakable.

When it comes to humans, PFAS have been linked to thyroid, liver, and reproductive problems, high cholesterol, cancer, and fetal anomalies. Studies have revealed that almost all Americans have detectable levels of the chemicals in their blood. The chemicals have accumulated in soil, water, and wildlife.

According to toxicologist Jonathan Petali of the New Hampshire Department of Environmental Services, co-author of the study, “PFAS are not limited to manufacturing, fire-fighting foams, or municipal waste streams—they are a decades-long global challenge.”. One of the first states to find PFAS in drinking water was New Hampshire. Because years have been spent looking into the effects of PFAS and attempting to reduce exposure, our state is rich in data. “.


Samples of the most popular marine species to eat, including cod, haddock, lobster, salmon, scallop, shrimp, and tuna, were subjected to measurements of 26 different PFAS types. The seafood under study came from different regions and was bought fresh from a market in coastal New Hampshire.

The researchers report that for some PFAS compounds, the highest concentrations were found in shrimp and lobster, with averages reaching as high as 1.74 and 3.30 nanograms per gram of flesh, respectively. Individual PFAS concentrations in different fish and seafood are typically less than one nanogram per gram.

The researchers note that it is challenging to pinpoint the precise location and mode of entry of PFAS into the marine food chain due to their widespread presence in the environment. Because they live and feed on the seafloor, certain shellfish may be particularly susceptible to the accumulation of PFAS in their flesh because of their close proximity to PFAS sources that are located close to the coast. By consuming smaller species that are more likely to have PFAS build up in their bodies—like shellfish—larger marine animals may come into contact with the chemicals.

The study is supported by a survey that the researchers carried out among 1,829 residents of New Hampshire to determine how much seafood Granite Staters consume—a lot, in fact.

According to the survey, women consume slightly less than one ounce of seafood daily in New Hampshire, while men consume slightly more. These values surpass the results of the National Health and Nutrition Examination Survey for both genders in the Northeast region, and are more than 1.5 times higher than the national average. The daily intake of children in New Hampshire, ages 2 to 11, was approximately 0 point 2 ounces, which is the highest amount among children across the country.

Ninety-five percent of the adults the researchers polled said they had eaten seafood in the previous year, and ninety-four percent of that group had eaten fish or shellfish the month before. Within the last week, over two thirds of the participants consumed seafood.

However, the seafood consumption of New Hampshire residents varies. Near the Massachusetts border or along the state’s coast, over half of those who consumed seafood in the week prior to the survey resided. Seafood was reported to be consumed at least once a week by more than 60% of respondents whose annual household income was less than $45,000, while those with higher incomes reported eating it less frequently.

Of the species that the researchers tested for per- and polyfluoroalkyl substances (PFAS), over 70% of the adults who ate seafood once a month or more reported consuming shrimp, haddock, and salmon. Just over 54% of these adults consumed lobster. The fish that kids ate the most frequently were haddock, canned tuna, salmon, and shrimp.

According to Celia Chen, a research professor in the Department of Biological Sciences and co-author of the study, there are federal guidelines for safe seafood consumption regarding mercury and other contaminants, but not PFAS.

We can limit exposure by using the knowledge that top predator species, like sharks and tuna, have high concentrations of mercury in them. However, the situation with PFAS is less clear, Chen notes. This is especially true when considering how the various compounds interact with the environment. Chen is in charge of multiple federally funded studies that investigate the locations and processes by which PFAS build up in aquatic food webs in Vermont and New Hampshire.

First author of the study and Middlebury College assistant professor of environmental studies Kathryn Crawford says that setting safety guidelines would help shield those who are particularly vulnerable to pollutants.

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