Fishing for Answers on Healthy Seafood

What are the best seafood choices for you?

Posted: 09-Mar-2004; Updated: 06-Feb-2007

Seafood lovers have recently faced a spate of bad news when it comes to toxins and pollutants in fish -- from the growing list of advisories issued by the Environmental Protection Agency (EPA) and reports of high mercury levels in canned tuna, to a study in the journal Science that found  higher levels of polychlorinated biphenyls (PCBs) and other contaminants in farmed salmon than in wild salmon. All this comes as health experts extol the benefits of fish's lean protein and abundance of heart-healthy omega-3s. Adding to the complexity of making good seafood choices, many of the fish we like to eat are overfished or farmed in a way that's ecologically damaging.

So what's a health-conscious diner with an environmental conscience supposed to do? To help consumers navigate the murky waters of choosing seafood that is both ecologically friendly and low in dangerous contaminants like mercury and PCBs, Environmental Defense has added new health information on our Seafood Selector.  For years, the Selector has provided guidance to consumers in making the right seafood choices for the environment. Our online resource now features comprehensive information -- never before available in one place -- on contaminated fish, including consumption advisories for seafood with relatively high levels of contaminants.

Finding the Facts

Our scientists obtained data on contaminants in fish tissue from over 40 government databases and scientific studies to determine the level of contaminants in common seafood items in the United States. EPA's risk assessment methodology for these contaminants was then used to generate fish consumption advisories.

As it turns out, the majority of fish that are high in contaminants also fall on our Eco-Worst Choices list for ecological reasons. Fish such as rock cod (Pacific rockfish) and many groupers - which are dangerously overfished - accumulate high levels of mercury as long-lived predatory fish high on the food chain. Farmed Atlantic salmon - which threaten wild salmon and steelhead populations - have high concentrations of PCBs, dioxins and pesticides.

The good news is that there are safer options. Wild Alaskan and most canned salmon, tilapia, catfish, sardines, anchovies, crawfish and many clams are plentiful, appear to be low in contaminants and have few ecological drawbacks. 

From Industry to the Oceans

Since the rise of industrialization in the late 19th century, human-made contaminants have spread throughout the globe, including our oceans. Even though some mercury occurs naturally in the environment, mercury pollution from industrial sources like coal-fired power plants has caused mercury levels in our air, land and water to rise dramatically.

PCBs and dioxins are highly toxic industrial pollutants that persist in the environment for years. Even though PCBs are no longer manufactured and releases of dioxins have declined significantly, both types of chemicals can still be found at relatively high levels in certain fish. Certain persistent pesticides also contaminate seafood. These four contaminants - mercury, PCBs, dioxins and pesticides - are the basis for more than 95% of the government fish consumption advisories in the United States.

Fish consumption is the primary way that people are exposed to mercury, and an important route of exposure for PCBs and other contaminants - all of which build up in our bodies over time. Some fish that are highly contaminated should be eaten infrequently, in small amounts or not at all.

Health problems that may result from eating contaminated fish range from small, hard-to-detect changes to birth defects and cancer. Mothers who eat contaminated fish before becoming pregnant may have children who are slower to develop and to learn. Women beyond their childbearing years and men face fewer health risks from contaminants than children do.

Bottom Line, Is Fish Safe For Me to Eat?

What does this all add up to? Do the health benefits of fish consumption outweigh the risks? "Eating fish, especially those high in omega-3 acids, is good for the heart. But consumers should be aware of the potential risks from contamination," said John Balbus, MD, MPH, the health program director for Environmental Defense. "Because the risks are generally greatest for developing fetuses and young children, women who are pregnant or of childbearing age and anyone preparing meals for young children should be most cautious.  For others, the safest choice in fish and how much they can eat will depend on their gender, age and body size."
 
How will consumers know just how much of a particular fish is the right amount? Our scientist, Dr. Rebecca Goldburg, an expert on ecological and food safety issues, says, "We've based our consumption advice on EPA's risk assessment methodology, which is designed to protect children as well as adults. For mercury, our advice errs on the side of safety for men and for women past childbearing age," Goldburg says. "For PCBs, dioxins and pesticides, the issue is somewhat different, since the consumption advice is based on the long-term risk of cancer, although these chemicals also have other harmful health effects.  In short, adults other than women who are or may become pregnant can consider slightly exceeding our recommended consumption limits in order to increase their omega-3 intake."  

For specific consumption advice, view our Health Alert chart for adults and the Health Alert chart for children.

Besides following our consumption advice, consumers can reduce certain contaminants (but not mercury) by following a few common-sense steps in preparing and cooking fish, such as removing the skin before cooking and by grilling rather than frying. (For more on this see Dioxins in Fish and Shellfish, PCBs in Fish and Shellfish and Pesticides in Fish and Shellfish.)

You can exert your consumer power and only purchase seafood that is both good for the environment and low in contaminants. You can also take action and tell EPA to curb mercury pollution from coal-fired power plants -- the largest single source of mercury emissions in the U.S.  And finally, spread the word on environmentally friendly seafood and share our printable PDF Pocket Seafood Selector with family, friends, your local fish markets and your favorite restaurants. 

Find Out More:

• Seafood Selector's Health or Hazard section
• Health Alert charts.  
• Mercury Pollution and Public Health
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