PFAS exposure from diets high in seafood may be underestimated

The findings of this study highlight the need for stricter public health guidelines establishing the amount of seafood that people can safely consume to limit exposure to perfluoroalkyl and polyfluoroalkyl substances. The researchers report in the journal Exposure and Health. This need is especially urgent for coastal regions like New England, where industrial legacies and PFAS contamination conflict with fish cultural preferences, the authors write.

“Our recommendation is not to not eat seafood. Seafood is a good source of lean protein and omega fatty acids. But it is also a source of PFAS exposure in humans. It may be an underestimate,” said Megan Romano, M.D., corresponding author of the study. Associate Professor of Epidemiology at Dartmouth's Geisel School of Medicine.

“Understanding this risk-benefit tradeoff for seafood consumption is important for people making dietary decisions, especially vulnerable populations such as pregnant people and children,” Romano said. Ta.

The study combined analysis of PFAS concentrations in fresh seafood with a statewide dietary survey in New Hampshire. National data shows that New Hampshire, along with all of New England, has the highest consumption of seafood in the country, making it ideal for understanding the extent of people's exposure to PFAS through seafood. It is a typical state.

“Most of the existing research has focused on PFAS levels in freshwater species that people do not primarily eat,” he says. “The impact of PFAS and other endocrine disrupting chemicals in drinking water on New England communities.” Professor Romano, who studies “We thought that was a knowledge gap in the literature, especially for New England where we know people love seafood.”

The study also leveraged New Hampshire's extensive data on the sources and impacts of PFAS, which are staples in consumer products such as plastics and nonstick coatings. PFAS are called eternal chemicals because their molecular stability makes them versatile and virtually indestructible.

In humans, PFAS have been linked to cancer, fetal abnormalities, high cholesterol, and thyroid, liver, and reproductive disorders. These chemicals accumulate in soil, water, and wildlife, and studies show that nearly all Americans have measurable amounts of them in their blood.

“PFAS is not limited to manufacturing, firefighting foam, or municipal waste streams. PFAS is a global challenge for decades,” said study co-author Jonathan Petali, a toxicologist with the New Hampshire Department of Environmental Services. “New Hampshire was one of the first states to identify PFAS in drinking water. We are a data-rich state because we have spent years studying the effects of PFAS and mitigating exposure.”

Researchers measured levels of 26 PFAS in samples of the most consumed marine species, including cod, haddock, lobster, salmon, scallops, shrimp and tuna. The seafood studied was purchased fresh from markets along the New Hampshire coast and comes from a variety of regions.

The researchers reported that shrimp and lobster had the highest average concentrations of 1.74 and 3.30 nanograms per gram of meat, respectively, for certain PFAS compounds. Concentrations of individual PFAS in other seafood have generally been measured at less than 1 nanogram per gram.

The prevalence of PFAS in the environment makes it difficult to know exactly where and how the chemicals enter the marine food chain, researchers report. Some shellfish may be particularly vulnerable to the accumulation of PFAS in their meat due to their feeding and living on the ocean floor and their proximity to PFAS sources located near the coast. . Larger marine animals can ingest PFAS by eating smaller species, such as shellfish, that tend to accumulate the compounds in their bodies.

This research is reinforced by a survey of 1,829 New Hampshire residents that researchers conducted to determine how much seafood Granite Staters eat. .

The study found that men in New Hampshire consumed just over an ounce of seafood per day, while women consumed less than an ounce of seafood. Both are higher than the results of the National Health and Nutrition Examination Survey of men and women in the Northeast, and both are more than 1.5 times the national average. Her daily intake for her children in New Hampshire, ages 2 to 11, was about 0.2 ounces, at the high end of the range for children nationwide.

About 95% of the adults the researchers surveyed reported eating seafood within the past year, and 94% of that group reported eating seafood within the past month. More than two-thirds of respondents ate seafood within the past week.

But people in New Hampshire don't uniformly eat seafood. More than half of those who ate seafood in the week before the survey lived on the state's coast or near the Massachusetts border. More than 60% of those with household incomes less than $45,000 per year reported that they consumed seafood at least once a week, while those with higher household incomes ate seafood less frequently. reported that there were few.

Among the fish species researchers tested for PFAS, shrimp, haddock, and salmon were consumed by more than 70% of adults who eat seafood at least once a month. Lobster was eaten by just over 54% of these adults. Salmon, canned tuna, shrimp, and haddock were the most commonly consumed species among children.

Federal guidelines for safe seafood consumption exist for mercury and other contaminants, but not for PFAS, said study co-author Celia Chen, a research professor in Dartmouth College's School of Biological Sciences. That's what it means.

“Top predators such as tuna and sharks are known to contain high concentrations of mercury, so we can use that knowledge to limit exposure. “When you start looking at how they behave in the environment, it's not so clear about PFAS,” says the federal government, which is investigating where and how PFAS accumulates in aquatic food webs in New Hampshire and Vermont. said Chen, who has led several projects funded by.

Kathryn Crawford, lead author of the study and assistant professor of environmental studies at Middlebury College, said establishing safety guidelines would help protect people who are especially vulnerable to the effects of pollutants.

“Recommendations regarding seafood consumption often provide more conservative advice for these populations than for others,” said Crawford, who began the project as a postdoctoral fellow in Dartmouth's Romano lab. said. “People who eat a balanced diet that includes more common and moderate amounts of seafood should be able to enjoy the health benefits of seafood without incurring undue risk of PFAS exposure.”