The Problem with PFAS in Fish
Per- and polyfluoroalkyl substances, or PFAS, are a class of human-made chemicals known as "forever chemicals" because they do not break down in the environment or the human body. They have been used since the 1940s in a wide array of industrial and consumer products, including non-stick cookware, food packaging, and stain-resistant fabrics. Due to improper disposal and runoff, these chemicals have become widespread pollutants, contaminating surface water and accumulating in the tissues of fish and other wildlife.
How PFAS Enter the Food Chain
PFAS enter waterways from various sources, including industrial discharges, wastewater treatment plants, and the use of firefighting foam. In aquatic ecosystems, fish absorb these chemicals from the water and through their diet. Unlike some contaminants that primarily accumulate in fat, PFAS are known to concentrate in protein-rich tissues, including the edible muscle meat of the fish. This biomagnification is particularly problematic in freshwater systems, where PFAS levels are often found to be much higher than in commercial ocean-caught seafood.
Health Implications of PFAS Exposure
Continuous exposure to high levels of PFAS has been linked to several adverse health outcomes in scientific studies. The health effects can range from reproductive issues and developmental delays in children to interference with the body's natural hormones and a reduced immune response. The long-term exposure from eating contaminated fish, especially for frequent consumers, can contribute significantly to a person's overall body burden of PFAS, potentially increasing health risks.
How to Make Safer Seafood Choices
Mitigating PFAS exposure from fish relies heavily on making informed purchasing decisions. Here are some of the most effective strategies to protect yourself and your family.
-
Prioritize Commercially Caught Ocean Fish: Federal and independent testing has repeatedly found that commercially sold seafood, including many common ocean fish and shellfish, contains significantly lower levels of PFAS than freshwater fish caught from local lakes and rivers. The vastness of the ocean helps dilute concentrations, while enclosed freshwater systems can act as traps for persistent pollutants.
-
Consult Local Fish Consumption Advisories: If you eat locally caught freshwater fish, it is essential to consult your state or tribal fish advisory program. Many states issue specific guidance for particular water bodies and fish species based on contaminant levels, including PFAS. This information is regularly updated and provides the most localized, accurate risk assessment.
-
Choose Lower-Risk Species: Diversifying your seafood choices is a key strategy for reducing overall exposure. Some species are generally considered lower-risk, while larger, predatory fish may carry higher loads of certain toxins, though PFAS accumulation is not always as simple as trophic level. When selecting seafood, consider these options:
- Wild-caught salmon
- Sardines
- Anchovies
- Oysters
- Mussels
- U.S. farmed shrimp
-
Consider Farmed vs. Wild: The debate between farmed and wild-caught fish is complex regarding contaminants. While some studies suggest farmed seafood has lower PFAS levels than wild-caught, the chemical load depends heavily on the specific farm's practices and location. In the U.S., farmed fish is generally more regulated, but it is always wise to research and source responsibly.
The Ineffectiveness of Cooking to Remove PFAS
Many people wonder if cooking can help reduce PFAS in fish. The answer is, unfortunately, no. Unlike some other contaminants like PCBs that can be found in fatty tissues and sometimes reduced by trimming and certain cooking methods, PFAS is not reliably removed by cooking.
Studies on the effects of cooking have shown mixed and often unreliable results. For example, while some studies found minor reductions in shorter-chain PFAS with boiling, they also observed increases in the concentration of other, more persistent PFAS like PFOS. This is likely because the cooking process can simply concentrate certain chemicals or leach them into cooking juices that are then discarded. Ultimately, relying on cooking to remove PFAS from fish is not an effective or recommended approach for reducing dietary exposure. The best way to reduce exposure is to avoid contaminated sources in the first place.
Comparison of Seafood Choices for PFAS Exposure
To help you visualize the choices, here is a comparison table outlining different seafood options and their general PFAS risk levels.
| Seafood Type | Typical Source | General PFAS Risk | Notes |
|---|---|---|---|
| Wild-Caught Freshwater Fish (e.g., Bass, Catfish) | Local lakes, rivers, streams | High | Levels vary significantly by water body; highly dependent on local advisories. |
| Commercially-Caught Ocean Fish (e.g., Cod, Tuna, Wild Salmon) | Broad ocean environments | Low | Significantly lower levels due to dilution and regulation. |
| Shellfish (e.g., Oysters, Mussels, Shrimp) | Ocean, estuary farms | Low to Variable | Low risk from most sources; check local advisories for shellfish from urban or industrial estuaries. |
| Farmed Seafood (e.g., Atlantic Salmon, Tilapia) | Aquaculture farms | Low to Medium | Generally lower levels than freshwater fish, but risk depends on feed and farm practices. U.S. farms are often more regulated. |
| Canned Tuna (Light vs. Albacore) | Commercial ocean fishing | Low | Light tuna generally has lower mercury; data on PFAS is less extensive but levels appear low. |
Actionable Steps for Reducing PFAS Exposure
- Check Local Advisories Regularly: Before fishing in a local lake or river, visit your state's health or environmental protection website for the latest consumption advisories. These are the most reliable indicators of local risk.
- Choose Commercial Ocean Fish: When purchasing fish from a grocery store, prioritize commercially caught ocean species. Look for certifications like the Marine Stewardship Council to ensure responsible sourcing.
- Embrace Shellfish: Oysters, mussels, and shrimp are generally considered low in PFAS and can be excellent sources of protein and nutrients. However, be cautious about sourcing from enclosed bodies of water with high industrial runoff.
- Cook Responsibly, But Don't Rely on It: Use PFAS-free cookware, such as stainless steel or cast iron. While cooking does not effectively remove PFAS from fish, it's still best practice to minimize all sources of exposure, including from non-stick coatings.
- Advocate for Regulation: Supporting stricter regulations on PFAS manufacturing and disposal can help reduce the amount of these chemicals entering the environment. Learn more about PFAS and advocacy efforts on the EPA website: https://www.epa.gov/pfas.
Conclusion
Navigating the presence of PFAS in our food supply requires awareness and proactive choices. While fish offers significant health benefits, it is clear that sources matter greatly concerning PFAS contamination. Consumers can significantly reduce their risk by making strategic seafood selections, with an emphasis on commercially caught ocean species over locally caught freshwater fish. Relying on regional consumption advisories is crucial for anglers. By staying informed and making conscious decisions, you can continue to enjoy fish as part of a healthy and varied diet while minimizing your exposure to these persistent environmental contaminants.
