TCS Daily

Fishy Advice -- Risk-Free at What Cost?

By Sandy Szwarc - April 26, 2004 12:00 AM

Editor's note: This is the second of a two part series on mercury. Read the first installment here.

Remember when women were encouraged to simply enjoy 2 or 3 servings of a wide variety of fish each week to ensure a healthy baby? Our babies aren't in any more danger today, what's changed is our fear.

When the FDA repeatedly issues health advisories spelling out dangers in increasing detail, as it's done the past few years, it's natural to assume the risks must be pretty significant. "Some fish and shellfish contain high levels of mercury that may harm an unborn baby or young child's developing nervous system," states the FDA's latest advisory. "The risks... depend on the amount of fish and shellfish eaten and the levels of mercury in the fish and shellfish."1-3

But not a single mother in America has ever eaten so much fish she's put her baby anywhere near harm's way. Yet the terminology being used by the government and the media certainly leads us to think that.

"We should be honest and truthful about how we are presenting the information to...the public," said Lawrence J. Fischer, Ph.D. at the FDA's Food Advisory Committee scientific meetings on methylmercury in 2002.4 In the new pursuit of zero risks, actual risk parameters based on evidence and reason have been replaced by extreme and arbitrary safety cushions.

Dr. James Heimbach, former associate administrator of the Human Nutrition Information Services, reminded the FDA Committee "that fish is not simply a carrier for methylmercury or....whatever we may be concerned about at the moment. It is a food. It is a food that is a very important part of the healthy diet. Both the American Heart Association and the American Dietetic Association, representing also the dieticians of Canada, have been recommending actually increasing consumption of fish."

Instead of promoting health and safety, the FDA's advisories may have had negative consequences. John Middaugh, State Epidemiologist with the Alaska Division of Public Health told the FDA Committee: "Advisories based upon risk assessment without consideration of well-established public health benefits of fish consumption have great potential to harm public health if reductions in fish consumption occur." He described how they've seen an abandonment of traditional fish diets among Alaskan communities since the FDA's 2001 mercury advisory, with subsequent major increases in diabetes, heart disease, and vitamin A and D deficiencies.4

Yet the FDA's 2001 advisory, like those in 2002 and 2003, was mild compared to their most recent one issued last month. It began by suggesting women of childbearing age avoid shark, swordfish, king mackerel, or tilefish (from the Gulf of Mexico not the Atlantic which are low in methylmercury).1-3 Then, unlike previous advisories that simply suggested women eat 12 ounces each week of a variety of types of fish, the latest proceeded with a complicated list of 5 varieties of fish low in methylmercury -- shrimp, canned light tuna, salmon, pollock and catfish (although it's a mystery why they arbitrarily chose those when hundreds of other varieties are equally low in methylmercury); offered descriptions and explanations of different tunas; and advised women that if they're eating 6 ounces of albacore tuna to then eat no more than 6 ounces of another fish that week....5

This author became confused midway through the fish lists and threw up her hands. For many consumers, fish sounds too scary to even bother to eat at all anymore. Understandably, pregnant women are especially alert to health advice. And they've been unnecessarily alarmed by these mercury warnings and deterred from eating fish or serving it to their children. A Harvard study released last August in The Journal of Obstetrics & Gynecology found that after the FDA's 2001 advisory, pregnant women dramatically reduced their consumption of fish and declines were ongoing.6

This concerns the American College of Obstetricians and Gynecologists which for over ten years has been urging women to eat fish for its abundant health benefits, according to Charles Lockwood, MD, former chairman. Greater fish consumption has been shown to improve pregnancy health outcomes and fetal growth and reduce the risk of preeclampsia and premature labor, Lockwood testified to the FDA Committee. Certain fish are also the richest sources of the omega-3 fatty acid, DHA, critical in the diets of pregnant women and nursing babies to ensure vision, behavioral and cognitive development.4

Incredibly, the FDA ignored these concerns and the weak evidence of actual risk and continued to sound the alarm.

Public Pressure Trumps Science

Several weeks before the latest FDA advisory, the Mercury Project of environmental groups at The Tides Center (National Environmental Trust, Waterkeeper Alliance, Consumers Union, Physicians for Social Responsibility, Natural Resources Defense Council (NRDC), National Wildlife Federation, Sierra Club and others) wrote public letters to the FDA urging stricter and more detailed advisories, especially targeting canned white tuna. For years, prior to each of their other mercury advisories the FDA and HHS Secretaries had been sent similar letters by these same groups and the Center for Science in the Public Interest.7-9 Also corresponding to the FDA's advisories, the Environmental Working Group (EWG), a special interest lobbying group, filed legal challenges against the FDA to block them from issuing weak mercury advisories.10

These groups have also used fears to apply public pressure. That legendary "60,000 babies annually are born at risk" tale has grown over the years. Last month, estimates of infants at "risk" had reached 630,000 and saturated media headlines.11-13 "More than one child in six born in the United States could be at risk for developmental disorders because of mercury exposure in the mother's womb," proclaimed the New York Times.

Jane Houlihan, with EWG and the Consumers Union, told the FDA Committee how the EWG arrived at these estimates. They took the highest methylmercury levels from the CDC's 1999 National Health and Nutrition Examination Survey and "added what would happen if women just ate fish with the highest limits of mercury."4 That, of course, completely disregards that FDA advisories emphasized women enjoy a variety of different types of fish. But scientists at the FDA methylmercury meetings were unable to reproduce the EWG's "astounding" results and pointed out multiple errors in their calculations. The EWG ignored the fact that a good number of women at the high end of mercury levels were already eating a lot of high-mercury fish, noted Margaret McBride, M.D., a pediatric neurologist from Rochester, NY. And some women with the highest mercury levels were found to have elevated levels due to sources other than fish. Alex Acholonu, Ph.D., a biologist at Alcorn State University in Mississippi, pointed out the EWG also failed to consider the half-life of methylmercury in their calculations, as mercury clears from the human body in about 70 days. As Heimbach noted, the EWG's figures went beyond biological plausibility.

It's Not Really About Fish At All

But creating concerns about mercury in fish helps fuel the efforts of environmental groups surrounding the emissions regulations under the Clean Air Act. The FDA's mercury warnings are being used as proof of a health threat. "If mercury is so dangerous that pregnant women are urged not to eat much fish, then it's time to get...tough on polluters," noted a Jan. 4, 2004 Baltimore Sun editorial.

Tuna fish sandwiches are their newest symbols of toxicity. You've probably seen the TV ads depicting a poison symbol morphing into a happy face on a child's lunchbox. They're part of the national ad campaign launched by Fenton Communications on March 26th for the EWG, NRDC and in their opposition to "[President] Bush's proposed 10-year mercury cleanup delay."14 These groups have also pursued state-level legislation and reported last month they'd helped introduce over 90 bills in 30 states. The legislation includes limits on the sale of mercury-containing products, labeling requirements and tougher rules for mercury emissions.15

Trouble is, many of the claims about mercury in fish and air emissions don't stand up to the evidence.

Where Does Mercury Come From?

Mercury is a naturally-occurring metal found in several forms: elemental, inorganic and organic. While environmental groups lead everyone to believe nasty American coal-burning power plants are to blame, actually most mercury comes from Mother Nature herself. Up to 6,000 tons are released each year from natural degassing of the Earth's oceans and crusts, as in volcanos, and forest fires. Methylmercury is one of the organic mercury compounds created with aquatic bacteria and is higher in freshwater than saltwater.16,17 Not all mercury compounds are alike, though, and they have different degrees of toxicity depending upon the molecules the mercury is bound to. Some research, such as that from biophysicist Graham George's published in last August's issue of Science, suggests that the methylmercury in fish may not be as toxic as once thought because it's in a form less likely to be metabolized and cross cell membranes.18

"Methylmercury has probably been in fish as long as fish have been on this planet," said Tom Clarkson, a toxicologist at the University of Rochester.19 But most levels are exceedingly low.17,20,21 The higher up the aquatic food chain -- as little fish get eaten by bigger fish -- the higher the methylmercury levels. So large ocean fish and freshwater bass, pike and walleye, at the top of their respective food chains, have higher levels than their smaller counterparts and can sometimes reach the FDA's safe limit for fish sold for human consumption. For recreationally-caught fish, the EPA monitors and issues local fishing advisories when high levels are found.22,23 Farm-raised fish contain especially low levels because of the mercury-free diet they are fed.24,25

Environmental mercury is undeniably a global issue. U.S. power plants contribute less than 1% of the global atmospheric mercury. Forty-two percent comes from man-made sources outside the U.S. -- Asia accounts for half, with China's power plants alone representing about 22%.22 U.S. industrial use of mercury has dropped more than 50% since 1991. Yet while emissions from our incinerators and other sources have decreased the past decade and continue to do so, mercury deposits in most areas of our country have remained fairly constant. That's because there's a global cycling of mercury in its various forms through the environment's waters, soils and air.21 Conversely, while global mercury emissions increased, methylmercury concentrations in marine fish have not. French scientists found methylmercury levels in Yellowfin tuna caught off Hawaii in 1998 measured the same as in 1971, despite their predictions of a 9 to 26% increase.26

Emissions and Politics

A review of the scientific evidence led the Annapolis Center for Science-Based Public Policy to conclude that further drastic reductions in U.S. emissions won't appreciably affect methylmercury levels in fish.22 This gives sound cause to weigh the negligible public health and environmental benefits of the Administration's Clear Skies Initiative -- as well as the even steeper reductions in power plant emissions environmental groups are demanding -- against any likely harm.

In a recent White Paper, the Center for Science & Public Policy found the attenuation of safe and reliable energy sources being prescribed would drive energy costs so high as to fatally endanger especially the lives and livelihoods of minorities, the poor and elderly -- as well as our national economy.27 The facts point to conclusions far different from the Administration's claims that 14,000 lives will be saved under Clear Skies as well as the environmentalists' accusations that it will "put an entire generation at risk."28

The truth is, the fearmongering from all sides is most harming the very people they're purporting to be protecting -- women and babies.


1. FDA Talk Paper, FDA Announces Comprehensive Foods Advisory on Methylmercury, Dec 10, 2003.

2. Overview of the Draft FDA/EPA Methylmercury (MeHg) Consumer Advisory, FDA, Dec 10-11, 2002.

3. FDA and EPA Development of a Joint Advisory for Methylmercury-containing Fish Consumption for Women of Childbearing Age and Children, July 2003.

4. Dept. of HHS, FDA, CFSAN. Food Advisory Committee - Methylmercury. Transcripts of meetings July 23-4, 2002.

5. What You Need to Know About Mercury in Fish and Shellfish -2004 EPA and FDA Advice For: Women Who Might Become Pregnant, Woman Who are Pregnant, Nursing Mothers, Young Children. HSS FDA, March 2004.

6. Oken E, etal. Decline in Fish Consumption Among Pregnant Women After a National Mercury Advisory. The Journal of Obstetrics & Gynecology, August 1 2003; 102 (2): 346-351.

7. Mercury Project letter to Secretary Donna Shalala, Jan 11, 2001.

8. CSPI letter to FDA Commissioner Jane Henney, Re:Petition to Set A Regulatory Limit for Methylmercury In Seafood That Reflects the Risk to Pregnant Women and Children From the Intake of Seafood Containing Methylmercury; July 17, 2000.

9. FDA Advisory Proposal Fails to Adequately Warn Public About Mercury in Tuna. National Resources Defense Council Press Release, Dec 11, 2003.

10. Environmental Working Group Files Legal Challenge to FDA Mercury Health Advisory. EWG Press Release, Dec 22, 2003. New FDA Seafood Advisory is Industry Giveaway - Statement from Environmental Working Group. EWG Press Release March 19, 2004.

11. Mercury study shows permanent damage to kids. Reuters, Feb 7, 2004.

12. New Study Reveals More Babies at Risk From Mercury. Organic Consumers Union, Feb 6, 2004.

13. Lee J. EPA Raises Estimate of Babies Affected by Mercury Exposure. New York Times, Feb 10, 2004.

14. Environmental Media Services. Bush's Next Arsenic? Media Advisory for Press Conference March 26, 2004.

15. News from Mercury Policy Project, Feb 19, 2004.

16. 2000 Mercury Report. Louisiana Department of Health and Hospitals; Louisiana Dept of Environmental Quality. July 2001.

17. Dalton LW. Methylmercury Toxicology Probed.Chemical and Engineering News, January 19, 2004; 82 (3): 701.

18. Harris HH, Pickering IJ, George GN. The Chemical Form of Mercury in Fish. Science; Aug 29, 2004; 301: 1203.

19. Wheeler M. Mercury. Environmental Health Perspectives; August 1996; 104 (8).

20. Barber M. Survey of metals and other elements. Food Standards Agency. Food Survey Information Sheet 48/04, March 2004. 21. US Dept. of Health and Human Services FDA and EPA. Mercury Levels in Commercial Fish and Seafood.

22. Koenig HM. Mercury in the Environment: The Problems, the Risks, and the Consequences. Annapolis Center for Science-Based Public Policy.

23. Questions and Answers About Mercury in the Environment and Food. IFIC, June 2002.

24. Santerre C. Experts say consumers can eat around toxins in fish . Purdue News, Feb 6, 2003. 25. Santerre C. Three-year study shows farm-raised fish safe. Purdue News, Jan 31, 2001.

26. Kraepiel AM; Keller K, Chin HB, Malcolm EG, Morel FM. Sources and Variations of Mercury in Tuna; Environmental Science & Technology; 2003; 37 (24): 5551-5558.

27. Walker LH. Analysis of the Sierra Club's Alarmist Claims about the Health Impacts of Mercury. Center for Science & Public Policy White Paper. 2004. 28. Environmental Media Services. Bush's Next Arsenic? Media Advisory for Press Conference March 26, 2004.


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