Balancing the Benefits and Risks of Seafood Consumption

A recent study by Dartmouth researchers has shed light on a potential health concern related to seafood consumption. The study, led by Megan Romano, an associate professor of epidemiology at Dartmouth’s Geisel School of Medicine, found that seafood could be a “potentially underestimated source of PFAS exposure” in humans.

5 Key Points

1. A Dartmouth study suggests that seafood could be a potentially underestimated source of PFAS exposure in humans.

2. The study found the highest PFAS concentrations in shrimp and lobster, with lower levels in scallops, cod, haddock, salmon, and tuna.

3. Researchers call for more stringent public health guidelines to establish safe seafood consumption levels and limit PFAS exposure.

4. The study surveyed 1,829 New Hampshire residents and tested commonly consumed seafood sourced from the Gulf of Maine.

5. The need for specific guidance on safe PFAS levels in food makes it difficult for consumers to make informed choices about seafood consumption.

PFAS, or perfluoroalkyl and poly-fluoroalkyl substances, are a class of artificial toxins that have been present in thousands of consumer products for decades. These “forever chemicals” can take hundreds of years to break down and have been linked to various health issues, including cancer, heart disease, and thyroid disease.

While the researchers emphasize that seafood remains a valuable source of lean protein and omega fatty acids, they stress the importance of understanding the risk-benefit trade-off, especially for vulnerable populations such as pregnant individuals and children.

Study Methodology and Findings

To conduct the study, researchers surveyed 1,829 New Hampshire residents to determine their seafood consumption habits, including frequency, portion sizes, and seafood types consumed. They then purchased the most commonly consumed seafood, such as shrimp, lobster, haddock, cod, salmon, and tuna, from a Portsmouth, New Hampshire seafood market. The seafood was primarily sourced from the Gulf of Maine and sold fresh the day it was caught.

The study found the highest PFAS concentrations in shrimp and lobster, with maximum concentrations ranging from 2.7 to 5.4 nanograms per gram (ng/g) for various PFAS compounds. Scallops, cod, haddock, salmon, and tuna had lower concentrations, ranging from less than the method detection limit to <1.0 ng/g.

Challenges in Establishing Safe PFAS Levels in Seafood

Despite the study’s findings, determining the danger posed by these PFAS levels to seafood consumers remains challenging. Romano notes that uniform nationwide safety levels for PFAS in seafood still need to be created, making it difficult for even well-informed consumers to make safer seafood choices.

One of the primary obstacles is the need for more specific guidance on safe or acceptable PFAS concentrations in food. Instead, available guidance is based on the amount of PFAS an individual can be exposed to daily from any source without detectable health risks. However, these values are only available for a limited number of PFAS compounds.

Tracing the Source of Seafood Contamination

Bonnie Brady, executive director of the Long Island Commercial Fishing Association, highlighted another challenge in addressing PFAS contamination in seafood: tracing the source of most popular seafood to where it was captured or contaminated.

Many popular seafood items, such as salmon and shrimp, are imported from various countries, making it challenging to pinpoint the source of contamination. Additionally, the migratory nature of some fish species further complicates efforts to track the contaminating source in a PFAS-infected fish accurately.

Implications and Future Steps

The Dartmouth study’s findings underscore the need for more stringent public health guidelines that establish safe seafood consumption levels to limit PFAS exposure. This need is particularly urgent for coastal regions like New England, where a legacy of industry and PFAS pollution intersects with a cultural preference for fish consumption.

As the U.S. Environmental Protection Agency (EPA) recently issued its first-ever PFAS standards for drinking water, mandating near-zero levels for six artificial chemicals within five years, attention may now turn to establishing similar guidelines for seafood.

While the study’s authors do not recommend avoiding seafood altogether, they emphasize the importance of understanding the potential risks and making informed choices, especially for vulnerable populations. As more research is conducted and public health guidelines are established, consumers can work towards balancing the benefits and risks of seafood consumption.