EPA’s Methymercury Report: Lawyers, Liability & Politics

The latest official document tossed into the public debate about methyl mercury and human health is being touted as yet one more damaging decree to be used against host of resource-use industries including seafood, energy, and mining.

Entitled, “America’s Children and the Environment,” the report issued by the U.S. Environmental Protection Agency reiterates the already established governmental concern about toxic methyl mercury, children and women of childbearing age. And, it repeats the EPA’s many references to coal-burning energy plants and industrial pollution as primary sources of environmental mercury. The emphasis on unknown health effects on the unborn and the pledge by the U.S. Centers for Disease Control (CDC) to regularly monitor methyl mercury levels in U.S. citizens are perhaps the reports’ only newsworthy aspects.

On the whole the public health concern over possible negative health effects of methyl mercury ingestion is not a new issue. It is one that has gained in contemporary importance thanks to the NGO-engineered legal actions aimed at grocery and restaurant chains operating in California that sell a variety of fresh fish such as swordfish, tuna, king mackerel, and tilefish. Those legal entanglements are allowed under California’s “Safe Drinking Water and Toxic Enforcement Act of 1986” more popularly known as Proposition 65 where fines up to $2500 per infraction may be levied.

The importance of the controversy surrounding the EPA report depends upon the reader’s point of view. Critics of U.S. President George W. Bush’s Administration cite the alleged nine-month delay in releasing the report as testament of the conservative Republican’s refusal to embrace the political agenda of environmental and animal rights activists for whom his predecessor, William Jefferson Clinton, skillfully pandered.

NGO’s attempting to extort hundreds of millions of dollars from seafood enterprises albeit quite legally via Proposition 65 also known as the “Bounty Hunter” law because penalties assessed for infractions can be paid directly to whoever turned the guilty party in see it as adding potent public and political pressure on their targeted victims to settle out of court. Purveyors of fresh seafood, whether they are grocers or restaurants, are not amused.

On the other hand, frustration is how serious public health investigators view the mix of lawyers, liability and politics that is misleading the public, government officials, judges, and public policy makers into thinking of the methyl mercury/human health in simplistic terms. The truth of the matter is that the effect of methyl mercury on human health is not as simple as this highly public debate suggests.

Extensive research is needed before any authority can credibly and justly levy penalties for current ingestion levels of methyl mercury related to seafood consumption under Prop 65. At present, the real reason potentially millions of dollars in penalties may be paid by corporations in California under that state’s anti-toxic chemical statutes is because of the precautionary principle, not sound medical research linking mercury in seafood with actual health problems. Unfortunately, that catch-all approach to the lack of human knowledge has become a barrier to research, not a catalyst.

Methyl mercury is the organic form of inorganic mercury and no one disputes its toxicity or the risks associated with susceptible elements within society: the unborn, children, pregnant women and women of childbearing age. But measuring methyl mercury (MeHg) content in blood or hair or even by the amount ingested is not an accurate indicator of whether or not a human’s health is in real or theoretical jeopardy.

The U.S. government’s long standing “reference dose” (RfD) of methyl mercury or, put another way, the level of acceptable ingestion of methyl mercury from sources such as seafood (0.1 ug/kg/day where ug is a microgram = 10-6 or 0.000001 of a gram) is intentionally low by what scientists call an “uncertainty factor” of 10. In a litigious society, accepted practice by legal counsel insists on built-in safety buffers that create a wide separation between what is real and what is perceived as a potential risk.

The problem with the debate in the U.S. is that research conducted by either the Centers for Disease Control (CDC) and the EPA suffers from a credibility deficit caused by the perception that both agencies tend to be easily manipulated by political rather than purely scientific concerns. Liberals see government agencies as too conservative. Conservatives view them as biased towards liberal points of view.

The most comprehensive U.S. survey of the toxic effects of methyl mercury was conducted by the National Research Council (NRC) on behalf of EPA in 2000. The NRC’s 344-page “Toxicological Effects of Methymercury,” cited the tragic incidents of fatal methyl mercury poisonings in Iraq and Japan between 1952 and 1979 when thousands of individuals died from mercury poisoning either from bread made from grain dusted with mercury powder fungicide or from fish caught in waters dense with industrial pollution. The EPA “reference dose” prior to 2000 was derived from information gleaned from studies of Iraqi deaths. The NRC study warned against the credibility of data associated with the Iraqi studies and chose instead three epidemiological studies in the Seychelles, Faeroe Islands and New Zealand for the RfD.

In fact, the truly most comprehensive studies of human health effects where high blood and hair levels of methyl mercury are present come from Canada. The Inuit population of that nation and the entire circumpolar area depend upon traditional diets of “country food:” marine mammals and fish with some of the highest levels of methyl mercury and other contaminants found anywhere on the planet. One, “The Influence of Nutrition on Methyl Mercury Intoxication,” illustrates the incredible complexity of conditions that increase or diminish the toxic effects of methyl mercury on humans.

A survey of research over two decades into a wide array of nutrients, nutrition supplements, diet, behavior, health levels, and their interaction with methyl mercury is summarized in great detail in that work. References are as intriguing as the purported fact that chewing hardboiled eggs decreases mercury vapor from amalgam tooth fillings while chewing gum increases the mercury vapor intake. Selenium and wheat bran can decrease mercury’s effects. Some nutrients speed the breakdown of organic methyl mercury into inorganic mercury which is then excreted via feces or urine. Some, like alcohol, increase toxicity. And there are other concerns such as the disruption of the natural mercury elimination system due to changes in intestinal processes when someone is taking antibiotics. According to that study, the lack of a healthy, balanced diet also brings enhanced negative consequences associated with methyl mercury ingestion.

When viewed against the multitude of effects nutrients, supplements, medicines, and diet have on methyl mercury and health, the importance and credibility of the recent study of San Francisco patients and methyl mercury from seafood conducted by Dr. Jane Hightower begins to pale. That study was used to precipitate the Proposition 65 legal action against five grocery chains in California. NGOs are also promising to bring a Prop 65 suit against the Red Lobster Restaurant chain thanks to the Hightower study. However, as even Dr. Hightower admits at the conclusion of her report, many factors other than or combined with methyl mercury could account for the complaints brought her by her patients. She admits that her methodology raised more questions than it answered.

One reference in the Canadian study that does bear directly on the U.S. controversy over swordfish and other fresh fish suggests that the NGO exhortation for commercial fishermen to capture only massive 250 pound and above swordfish is completely wrong-headed. Aside from the fact that the larger fish are invariably female breeders and that mature males are considerably smaller of stature, the larger fish accumulate greater concentrations of methyl mercury in their body mass. NGOs, campaigning to protect swordfish and who also urge commercial fisheries to only take larger fish, are actually working against themselves. Many of those same NGOs claiming to be concerned over the health of humans consuming swordfish are in fact urging use of a potentially greater vector for conveying methyl mercury to consumers when they insist on catching and selling only giant specimens of the majestic fish. On an environmental note, killing females is no way to build gross numbers of any species.

The multi-year (1991-1997) Canadian study of contaminants in the diet of Arctic people, the Canadian Arctic Contaminants Assessment Report or CACAR, presents an alarming array of compounds found in fish and marine mammal meat, blubber and skin that makes up the traditional diet of Canada’s northern most people. They include persistent organic pollutants (POPs) that include organochlorine pesticides such as toxaphene, chlordane, and DDT; polychlorinated biphenyls (PCBs) from abandoned military Distant Early Warning (DEW) radar sites; heavy metals such as mercury and cadmium; as well as radionuclides from the atmospheric nuclear weapons testing of the 1950s and 1960s, the Chernobyl nuclear reactor tragedy of 1986, and natural radioactive decay of uranium and thorium found in minerals throughout the northern reaches of Canada. That is a daunting load of contaminants for any palate.

Inuit and other aboriginal people of the Arctic north thrive on their “country food” diets and suffer outbreaks of southern maladies such as diabetes and cardiovascular disease when forced to switch to the foods of the people where beef, hogs, chickens, crops, and trees grow. While the people of the North condemn the glut of pollutants filtering to the top of the world from the industrial and personal waste of southern dwelling humans, they opt not to change their diet. Despite the fact that most nutrition/public health investigators would not dare suggest such high levels of contaminants found in northern diets are acceptable for southern cultures, the investigators participating in the CACAR study refused to recommend a dietary change for the Inuit and other first people groups studied.

Researchers, who could arguably be described as astonished at the spectrum and levels of contaminants in “country food” of the northern people, nevertheless see greater benefits than risks in the continuation of breast feeding newborns and from retaining traditional diets. The six-year study found “no observed adverse human health effects directly attributed to exposure to methyl mercury in the Canadian Arctic.”

No one is suggesting that fish oil capsules be substituted for the more potent seal oil capsules (forbidden in the United States under the Marine Mammal Protection Act) for an Omega3 health boost, or that Arizona grocers stock whale or walrus blubber. Nor can possible health problems attributed to methyl mercury consumption be dismissed as fantasy. The message that needs to be infused throughout the controversy over methyl mercury, fresh fish and human health is that the issue is highly complex and that the risks avoided by shunning fresh fish may not be as significant as the benefits gained from its consumption. The white hot furor being fanned over this issue needs to die down and an attitude of moderation, equilibrium and a desire to quench the thirst for knowledge replace it.