Parent: Food Safety
Food Safety: Mercury in Fish
Last edited by OrangeClouds115, November 12, 2007
Brain Food: Methylmercury
The EPA warns:
Americans are exposed to methylmercury primarily by eating contaminated fish. Because the developing fetus is the most sensitive to the toxic effects of methylmercury, women of childbearing age are regarded as the population of greatest concern.The majority of mercury polluting our waterways comes from coal-fired power plants that have not yet adopted technology to control the amount of soot, smog, and mercury pollution they spew into the atmosphere; other significant sources include municipal and medical waste incinerators. Once the mercury finds its way into the air, it comes back to the earth when it rains, seeping into lakes and streams.
Children who are exposed to methylmercury before birth may be at increased risk of poor performance on neurobehavioral tasks, such as those measuring attention, fine motor function, language skills, visual-spatial abilities and verbal memory.
This mercury becomes methylmercury when microorganisms in the water "methylate" it. Then methylmercury works its way up the food chain, lodging itself in the muscle of fish. As a rule, the higher up the food chain you go, and the longer the fish lives, the more the methylmercury in the fish.
How Much Fish Can We Safely Eat?
Which fish are safe to eat and how frequently can we eat them? It's a trick question, because the answer is as infinitely complicated as there are people on earth and fish in the sea.
First consider the different people who wish to eat fish. They vary in body weight, blood volume, and metabolism. Some are small children, some are women, and some are men. Of the women, some are pregnant, some are nursing mothers, and some may become pregnant within the next year.
Your body can rid itself of methylmercury, but the process requires time - a woman planning to become pregnant in the next year should not eat so much fish now that her body contains toxic levels of mercury at the start of the pregnancy. In fact, in 2004, 8% of women of childbearing age had unsafe levels of mercury in their blood.
Next consider the fish. Within a species of fish, each individual fish varies in mercury concentration. The government performed an analysis of many species of fish and posted the results online (you can see it at http://www.cfsan.fda.gov/...).
A Test: Eating The Recommended Amount of Albacore Tuna...
What if an 120 lb woman ate the government-recommended amount of albacore tuna? The current joint recommendation from the FDA and the EPA allow her, assuming she is of childbearing age, to have 6 oz of canned albacore tuna a week.
The EPA adds that they recommend a maximum of 0.1 micrograms of mercury per kilogram bodyweight per day, a standard supported by the National Academy of Sciences. That means she must have less than 5.44 micrograms of mercury per day, or less than 38.08 micrograms of mercury per week. If 6 oz. of canned albacore tuna has less mercury than that, then the federal recommendation will be accurate - so long as she doesn't eat any other fish with mercury in it all week.
Unfortunately, the average 6 oz serving of albacore tuna has 60 micrograms in it - about one and a half times what she should consume in a week. And don't forget that fifty percent of canned albacore tuna has less mercury than that, and fifty percent of canned albacore tuna has more.
In order to safely eat a 6 oz. serving of albacore tuna (assuming it contains the average amount of mercury or less), a woman of childbearing age would have to weigh 190 lbs. For reference, a woman weighing 190 lbs would be overweight based on her body mass index (BMI) unless she was taller than 6'1" - far taller than your average woman. And still, even if the average can of albacore tuna were safe for the average person, what about the two percent of cans on the shelf that contain between 102.9 and 124.3 micrograms of mercury per six ounce serving?
One Size Fits All Advice For Americans
The Environmental Working Group modeled a study, accounting for variation in body weight, blood volume, diet, and metabolism. They concluded that pregnant women, nursing mothers, and all women of childbearing age should not eat:
- tuna steaks
- sea bass
- oysters from the Gulf Coast
- marlin
- halibut
- pike
- walleye
- white croaker
- largemouth bass
- shark
- swordfish
- king mackerel
- tilefish
- canned tuna
- mahi-mahi
- blue mussel
- Eastern oyster
- cod
- Pollock
- salmon from the Great Lakes
- blue crab from the Gulf of Mexico
- wild channel catfish
- lake whitefish
The most dedicated among us print wallet cards of fish lists off the internet to carry to restaurants and grocery stores, but is that the right solution if it leaves as many as 630,000 babies born each year at significantly increased risk of neurological effects? (That number was taken from a 2004 presentation by Kathryn R. Mahaffey at the EPA - her slides are online, thank you Google)
The FDA and Tuna: Caught Pants Down, In Bed Together
The advice to Americans must be simple enough to remember and follow. That means the government can go in one of two directions: they can play it safe for consumers, or they can play it safe for the fishing industry.
The government can take the most egregious types of fish off the market, for example. Or, they can flat out tell consumers to avoid eating certain types of fish altogether. In fact, they can require warning labeling on menus, cans of tuna, and grocery store seafood counters, kind of like warning labels on packages of cigarettes.
No doubt that any one of these approaches would prevent someone from enjoying a seafood dinner that would never cause him or her any harm. The seafood industry, from the fishermen to the seafood restaurants, would also feel pain. The question we must ask is whether such an inconvenience is worth the lives of unborn children saved from neurological defects.
The FDA was aware that their message must be crafted in a way that consumers could understand and follow it so they held focus groups before coming out with a set of recommendations in 2000. Prior to issuing the 2001 alert, the FDA kicked around a suggested limited intake of tuna steaks and canned tuna.
When they issued the alert, it contained no references to tuna at all - only an advisory, alerting women who are pregnant, nursing, or who may become pregnant to avoid shark, tilefish, swordfish, and king mackerel entirely, and a recommendation to limit overall fish or shellfish consumption to 12 ounces per week. They claimed they left tuna off the advisory because too long a list of fish to avoid confuses women.
When the Environmental Working Group filed a Freedom of Information Act, they caught the FDA with their pants down, in bed with the tuna industry. The focus groups had shown that if women were told to limit their consumption of tuna, most would do exactly that and most would not give up fish entirely - the desired behavior the FDA hoped for.
During the fall of 2000, the FDA met privately with Chicken of the Sea, StarKist, Bumble Bee, U.S. Tuna Foundation, and National Food Processors Association three times, and removed all references to tuna in their 2001 advisory.
In 2004, the FDA supplanted their 2001 advisory with their joint FDA and EPA advisory, adding only that 6 ounces of a woman's 12 ounces of fish or shellfish per week can be albacore tuna. The Environmental Working Group came out with a statement saying, "After three years of bureaucratic wrangling, bungling and backpedaling, the FDA has actually made a bad situation worse, by encouraging consumption of albacore tuna at clearly unsafe levels."
The Real Solution: Stop Mercury Emissions
The irony is that the fishing industry taking the heat for something that someone else - coal-fired power plants - did wrong. They should use some of the clout they clearly have in Washington to get coal-fired power plants to stop polluting their fish.
Until we achieve a significant reduction in emissions, any other solution we put on the problem is merely a band-aid, be it education campaigns, warning labels, or even banning the sale of the most toxic kinds of fish.
Back in December of 2000, the EPA, ruling that coal-fired power plants violated the Clean Air Act, proposed a 90 percent reduction in mercury emissions by power plants by 2008. In 2003, political appointees from the Bush administration reversed that decision, giving the power plants until 2018 (instead of 2008) to reduce their emissions by 70 percent (instead of 90 percent).
Recipe For America supports honest FDA/EPA alerts to seafood consumers regarding methylmercury. Additionally, the government should take action now to halt the construction of more coal-fired power plants and require existing ones to reduce their emissions substantially.
TAKE ACTION: If you wish to continue eating fish without endangering your health or the health of your children, visit the websites listed below as resources to determine which fish are safest. Some sites include wallet cards which you can print and carry with you.
Additionally, you can take action by calling or writing your representatives and asking them to better regulate coal-fire power plants and more honestly educate consumers about mercury in fish. Be aware of any plans to build new coal-fired power plants in your community and take action to prevent their construction.
More information
DailyKos: Proof Bush Hates Fetuses (blog entry)EPA: Clean Air Mercury Rule (web site)
How Much Mercury Is In Fish? (Raw Numbers) (web site)
NYT: High Mercury Levels Are Found In Tuna Sushi (article) January 23, 2008
Ring of Fire Radio: Mercury Poisoning in Adults, Part 1 (news piece) Click this link to listen to an interview with Daphne Zuniga, who suffered mercury poisoning from the seafood in her diet.
Ring of Fire Radio: Mercury Poisoning in Adults, Part 2 (news piece) Click this link to listen to the second half of the interview with Daphne Zuniga.
Take action
Blue Ocean Institute: Guide to Ocean Friendly Seafood (web site)Environmental Working Group: Tuna Calculator (web site) How much tuna can you safely eat?
Get Tested for Mercury Contamination (web site)
Monterey Bay Aquarium: Seafood Watch (web site) Regional guides of the latest information on sustainable seafood choices
Oceans Alive: Best & Worst Seafood Choices (web site)
The Fish List: An Ocean-Friendly Guide to Making Better Seafood Choices (web site)
