Seafood lovers could face increased exposure to ‘forever chemicals’
Fears of mercury or PCBS might already have you thinking twice about eating fish despite the health benefits and culinary enjoyment. As if these chemicals weren’t enough to worry about, recent research suggests more contaminants should be considered when weighing consumption.
In January, researchers with the non-profit Ocean Conservancy and the University of Toronto found that nearly 90 per cent of proteins, including seafood, contained microplastics.
Based on American consumption data, this amounts to 3.8 million microplastics per year from animal and plant protein alone. Now, a new study has found that people who often eat seafood may be at a greater risk of exposure to PFAS, a large group of human-made toxins known as “forever chemicals,” than previously thought.
Megan Romano, the study’s corresponding author and an associate professor of epidemiology at Dartmouth College’s Geisel School of Medicine in New Hampshire, highlighted that most research had focused on PFAS levels in freshwater species, “which are not what people primarily eat. We saw that as a knowledge gap in the literature, especially for a New England state.”
Their findings, published in the journal Exposure and Health, underscore the need for public health guidelines so people know how much seafood they can eat to limit their exposure to PFAS. The researchers write that this is an especially urgent need in coastal regions where industry and PFAS pollution converge with a love of seafood.
“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,” said Romano.
“Understanding this risk-benefit trade-off for seafood consumption is important for people making decisions about diet, especially for vulnerable populations such as pregnant people and children.”
The researchers purchased samples of the most popular marine species — cod, haddock, lobster, salmon, scallop, shrimp and tuna — from a market in coastal New Hampshire and measured the levels of 26 types of PFAS. Shrimp and lobster had the highest concentrations, with averages as high as 1.74 and 3.30 nanograms per gram of flesh, respectively. Other species generally had less than one nanogram per gram.
Perfluoroalkyl and polyfluoroalkyl substances, or PFAS, are found in everyday consumer products. Since their invention in the 1930s, they have leaked into the soil, water and air. Studies have shown associations between PFAS exposure and a range of health conditions, such as cancer, fetal abnormalities, kidney and liver disease, and disrupted endocrine function.
“PFAS are not limited to manufacturing, firefighting foams, or municipal waste streams — they are a decades-long global challenge,” said study co-author Jonathan Petali, a toxicologist with the New Hampshire Department of Environmental Services.
Because they’re so prevalent, it’s challenging to know where and how the chemicals enter the marine food chain, the researchers write.
Shellfish may be hardest hit because they are near sources of PFAS on the coastline and feed and live on the ocean floor.
In May 2023, Environment and Climate Change Canada and Health Canada published a draft State of PFAS Report, and the latter agency is “consulting the public on a draft objective for PFAS in drinking water, which recommends a maximum level for total PFAS.”