The Problem with Mercury

Mercury pollution offers us a well-lit window into the failed system of chemical regulation in the U.S.

Mercury was discovered harming humans in Japan starting in 1953 — 53 years ago. Hundreds of people were affected by severe brain damage, blindness, and horrendous birth defects — all from eating fish heavily contaminated with mercury dumped into Minimata Bay by the Chisso Corporation. Birds and cats were afflicted with the same symptoms.

Ten years later, researchers in Sweden were systematically scouring the countryside, finding dead birds with elevated mercury in their blood. This time the culprit was seeds treated with mercury-containing fungicides. In 1966 Swedish researchers held a conference in Stockholm to present their findings and issue warnings — mercury levels in the environment were rising ominously, partly because of the use of mercury in pesticides, and partly for reasons unknown. The U.S. government sent representatives to the Stockholm conference, but they returned home without making a peep.

In 1969, Environment magazine told the story of mercury in Japan and Sweden and openly speculated that mercury would be found throughout the environment of the U.S. if anyone took the time to look for it. No one did.

Then in February, 1970, the Huckleby family in Alamogordo, New Mexico was poisoned by a batch of mercury-treated seed that they had fed to their hogs, which provided the family’s ham and bacon. Three Huckleby children were severely injured — one deafened, another was blinded, a third arriving at the hospital raving mad. The story made national news and within 24 hours the U.S. Department of Agriculture (USDA) wrapped up “10 years” of research on the dangers of mercury and declared mercury-containing pesticides an “imminent hazard.” Within days USDA canceled the registration of mercury-containing pesticides and demanded that the manufacturer recall the product from store shelves.

A month later. Norvald Fimreite — a graduate student at Western Ontario University — revealed that fish in many lakes along the <U.S.-> Canada border were contaminated with mercury at high levels (7 parts per million, for example). Ohio closed its portion of Lake Erie to commercial fishing. On June 18, 1970 Secretary of the Interior Walter Hickel declared mercury “an intolerable threat to the health and safety of the American people” — a statement so true and bold that it remains the quintessential summary of the mercury problem 35 years later.

Later that same year, 1970, a public interest research organization in Albuquerque, New Mexico — Southwest Research and Information Center (SRIC) — arranged to take samples from the stack gases emitted from the Four Corners coal-burning power plant and analyze them for mercury. SRIC’s staff scientist, Charles Hyder, was convinced that burning coal was the major source of mercury in the natural environment. The Four Corners tests proved him right. The Associated Press reported the results — that burning coal releases enormous quantities of mercury — but no one with any authority raised an eyebrow, much less a finger. (Disclosure: I worked with Hyder on that project.)

Meanwhile, Norvald Fimreite’s lonely work around the Great Lakes had aroused the world. Researchers began looking for mercury in fish everywhere. Soon everyone knew that big fish — fresh and saltwater, both — contain dangerous amounts of mercury: big walleye, big swordfish, big tuna, big grouper, big pike. Obviously, mercury was concentrating as it moved up the food chain. People began to realize that at the top of the food web you find big bears, large birds, and humans.

Soon the U.S. Food and Drug Administration established an “interim” standard, setting 0.5 parts per million (ppm) as the maximum allowable concentration for mercury in fish. It seemed as if science and good sense had prevailed to protect the public.

But then the U.S. regulatory system began to work just as it was designed to: in 1977, the nation’s swordfish distributors took the FDA to court, demanding that FDA stop seizing swordfish that exceeded the 0.5 ppm limit. The trial lasted four days and when it was over a federal judge had effectively doubled the nation’s allowable limit on mercury in fish, to 1.0 ppm.

Instead of building a scientific and precautionary case to protect the public, to prevent harm, the FDA caved in to the food distribution industry. In 1979, the FDA announced in the Federal Register that it was formally adopting 1.0 ppm as the new standard for mercury in fish, based in new data provided by the Commerce Department, showing that Americans didn’t eat as much fish as the FDA had thought.

Relaxing the acceptable level of mercury in fish, the Commerce Department said (and the FDA repeated), would “provide a significant economic benefit to those industries most seriously affected” by the more stringent limit and “enhance the future development of a number of presently underutilized fisheries.” Moreover, Commerce and FDA said, a less restrictive rule “would significantly increase consumer confidence in seafood.”

As the public grew more health-conscious, the consumption of seafood steadily rose, and the FDA turned a blind eye to questions of safety. The FDA essentially went to sleep for 12 years until a report from the National Academy of Sciences embarrassed it again in 1991. At that point FDA began testing fish to see how much mercury they contained, and the agency repeatedly promised to revisit its 1.0 ppm limit on mercury in fish, but it never actually got around to it. That 1979 limit still holds today.

In 1997, U.S. EPA set a mercury limit in fish that was four times as strict as the FDA’s, but EPA only had the power to inform consumers of the danger of eating mercury-contaminated fish. In 2000 the National Academy of Sciences endorsed EPA’s findings. Once again, FDA was being shamed into reviewing its 1979 mercury limit. But again the food distributors had their tentacles deep inside FDA. As Peter Waldman of the Wall Street Journal (WSJ) reported August 1, 2005,

“When the FDA issued a revised mercury advisory in 2001, it urged women of childbearing age to shun four high-mercury species: swordfish, shark, king mackerel and tilefish from the Gulf of Mexico. It didn’t mention tuna. Yet cumulatively, according to data provided by the EPA, the four species it urged avoiding account for less than 10% of Americans’ mercury ingestion from fish, while canned tuna accounts for about 34% of it.” And FDA concluded that it should stick with its 1979 recommendation, outlawing the sale of fish containing over 1.0 ppm of mercury.

Why did the FDA not mention canned tuna? The WSJ points out, “Food companies have long lobbied to mitigate any FDA action on canned tuna, one of the top-grossing supermarket items in revenue per unit of shelf space.”

The WSJ reported that even some EPA scientists concluded that FDA was coddling the fishing industry: “They really consider the fish industry to be their clients, rather than the U.S. public,” says Deborah Rice, a former EPA toxicologist who now works for the state of Maine.

But in April 2003, FDA caved in to mounting evidence of harm to children, announcing that it would consider adopting the EPA’s stricter guidelines for mercury in fish. Later that year FDA and EPA proposed issuing a joint-agency advisory for consumers. The WSJ reported what happened next:

“At the hearing, FDA scientists said they had put fish in three categories: high in mercury, medium and low. The level for the low- mercury group was that of canned light tuna, explained FDA official Clark Carrington. ‘In order to keep the market share at a reasonable level, we felt like we had to keep light tuna in the low-mercury group,’ he said, according to the meeting’s official transcript.

“Later, the FDA’s Dr. Acheson (director of food safety and security) reiterated that point. He told the meeting the fish categories ‘were arbitrarily chosen to put light tuna in the low category.’…

“Says Maine’s Dr. Rice: ‘Here’s the FDA making what are supposed to be scientific decisions on the basis of market share. What else is there to say?,’ WSJ reported.

The joint FDA-EPA advisory was finally released and it did warn against eating too much albacore tuna but it did not identify other high-mercury species like yellow fin tuna, orange roughy, grouper, marlin and walleye.

In late 2005, the Chicago Tribune investigated FDA’s history of work on mercury and concluded, “The Tribune’s investigation reveals a decades-long pattern of the U.S. government knowingly allowing millions of Americans to eat seafood with unsafe levels of mercury.”

The Tribune revealed that the tuna industry often packages a high- mercury fish (yellow fin tuna) but labels it “light tuna” which falls into FDA’s “low mercury” category (because, as we have seen, FDA created its categories specifically to make sure “light tuna” ended up in the “low mercury” category). So far, this yellow fin deception has escaped the notice of the FDA.

Although FDA has the legal authority to seize fish that exceed 1.0 ppm mercury it almost never does so because it almost never tests any fish — especially not imported fish, which makes up about 80% of all the fish sold in the U.S. The Chicago Tribune tested 18 fish from each of eight Chicago supermarkets, conducted some simple calculations using formulas provided by FDA, and concluded, “Some samples of grouper, tuna steak and canned tuna were so high in mercury that millions of American women would exceed the U.S. mercury exposure limit by eating just one 6-ounce meal in a week.”

The Tribune reported,

“Many experts now believe that even tuna-fish sandwiches — a favorite of the American diet — can be risky for children.

“‘The fact that we poisoned our air and our oceans to such an extent that we can’t eat a damn tuna sandwich is just diabolical,’ said Ayelet Waldman, a noted mystery author whose daughter was diagnosed with mercury poisoning at age 5 after frequently eating tuna.”

She was eating one tuna sandwich per week made from albacore tuna.

It turns out that mercury poisoning far more common than you might think. In early 2004, EPA revised its estimate of the number of newborn babies with enough mercury in their blood to cause learning disabilities, sluggishness, and other neurological problems. Prior to 2004, EPA thought “only” 8% (1 in 12) newborns were in danger if having their brains damaged by mercury. Now EPA believes 16% of U.S. newborns, 1 in 6, may be victims of mercury poisoning. In real numbers, this means that 630,000 newborns each year (out of 4 million) may be somewhat impaired even before they start the long journey of life.

Furthermore, a small study by Ellen Silbergeld at Johns Hopkins University seems to indicate that adults can be harmed by mercury as readily as children can. “Adults may be just as sensitive to mercury as children,” says Silbergeld, who studied neurological function in 52 men and 77 women living in fishing villages downstream of gold mines in Brazil.

In the U.S. mercury contamination is widespread, just as Environment magazine predicted in 1969. In 2002, at least 43 states issued mercury warnings for fish covering 12 million acres of lakes and 400,000 miles of rivers.

You might think that keeping mercury out of the natural environment, to the extent possible, would be a top public health priority of U.S. chemical regulators, but you would be mistaken.

Everyone now agrees with Charles Hyder that the biggest single human- created source of mercury in the natural environment is coal-burning power plants, which emit 48 tons of mercury each year in the U.S. This is a technical problem — the mercury can be removed from the coal before burning, or it can be captured before it escapes up the smoke stack. But of course the coal industry — famous for claiming it is now the “clean coal” industry — resists every effort to try to clean up its mercury emissions. The issue? Just money.

Early in 2005, two researchers calculated that the average reduced IQs of U.S. babies caused by mercury in their mothers could be translated into dollars of lost earnings over their lifetimes: $8.7 billion per year is the price tag on diminished IQs, they concluded.

When EPA considered issuing new rules to force coal-burning power plants to reduce their mercury emissions, EPA hid the results of a study they had commissioned by Harvard University researchers. The Harvard study had concluded that reducing mercury emissions carried a huge public health benefit and therefore EPA would be justified in clamping down hard on the coal-burners. By hiding this study from the public, EPA tried to claim that the health benefits would be minimal and therefore the power industry shouldn’t be required to spend large sums. When asked about all this by the Washington Post in early 2005, EPA officials simply lied, saying the Harvard study had arrived late and was flawed. Neither claim was true and EPA officials knew it at the time they said it.

EPA had said the cost to the coal-burners would be $750 million per year, but the health benefit would be only $5 million per year, so cleaning up mercury emissions from coal plants wouldn’t be worth it. The Harvard crew calculated that the health benefit would be $5 billion each year — making it well worth everyone’s while to clamp down on mercury emissions from coal.

Without apology, EPA and FDA continue to waffle, fudge and fake it — doing their best to protect the coal industry at the expense of the nation’s children and the nation’s future. That’s chemical regulation, U.S. style.

PETER MONTAGUE is editor of the indispensable Rachel’s Health and Democracy, where this essay originally appeared. He can be reached at:



Peter Montague is a fellow with the Science & Environmental Health Network, living in New Jersey.