The late singer-songwriter Laura Nyro loved to eat tuna fish. An avid environmentalist, she was shocked to hear that her favorite food was contaminated with the toxic heavy metal mercury, and she expressed her anger in a song. "I'm young enough, I'm old enough in the city machine/ Where industries fill the fish full of mercury (it's tax free)."

Nyro was right to worry about eating fish, and right about industrial mercury use. Forty states have issued advisories about eating fish that may have high levels of mercury in their tissues. As recently as last July, Massachusetts public health officials warned young women and children under 12 to stop eating "most" fish caught in state rivers and lakes, and to avoid certain seafood. Tuna was on the list, as was swordfish.

Mercury is a persistent heavy metal, processed into a liquid from mined cinnabar, that accumulates in water and in the tissues of humans, fish and animals. It was declared a hazardous air pollutant by the Environmental Protection Agency (EPA) in 1971.

According to the federal Agency for Toxic Substances and Disease Registry, long-term human exposure to mercury in either organic or inorganic form "can permanently damage the brain, kidneys, and developing fetuses." A potent neurotoxin, mercury is slowly being phased out of many commercial uses, including consumer thermometers, but it is still used in many industrial processes and is in such products as fluorescent lights, home and appliance thermostats, and even toys.

Ask most people about mercury in the environment and they're apt to think of broken thermometers. But the truth is that industry, in the form of coal-fired power plants, electric arc furnaces (which melt and recycle the steel from old cars) and municipal waste incinerators are the major sources. In landfills and in water, bacterial contamination turns mercury into its most toxic form, methyl mercury.

Mercury also gets into the environment in pharmaceutical products, and through ritual religious uses, especially in Latin American Santeria. Mercury sells for less than $2 a pound on the wholesale market, and even when it is "recycled," it may still end up in the environment.

Progress is being made to end some of mercury's more visible uses, but the campaign is far from over. Five states have laws that either put some restrictions on mercury use, sale or disposal or require labeling of products containing it. Similar bills are pending in 15 state legislatures.

"Despite state and local bans, thousands of retailers still sell mercury thermometers to consumers who aren't aware of the risks," says Felice Stadler, policy coordinator of the National Wildlife Federation's Clean the Rain campaign.

"Just one seventieth of a teaspoon of atmospheric mercury can contaminate a 20-acre lake for a year," says Michael Bender, executive director of the Vermont-based Mercury Policy Project. "We have to take mercury permanently out of commerce. It's not that difficult to containerize it and store it indefinitely. An ideal solution would be the kind of 'producer responsibility' laws they have in Europe, which make companies responsible for their waste."

U.S. Senator Susan Collins (R-ME) has proposed legislation that would create a task force to address the mercury problem on a national scale. Under her bill, the Mercury Reduction and Disposal Act, S.351, the sale of thermometers containing the metal would be banned nationally, and the mercury inside them would be stockpiled and treated similarly to nuclear waste. Stadler says, "Enacting a nationwide ban on sales is essential."

In response to a campaign led by Health Care Without Harm (HCWH), five drugstore chains, including CVS, Rite-Aid, Walgreens, Wal-Mart and Eckerd, have agreed to stop selling mercury thermometers. These companies represent 71 percent of chain pharmacies, but mercury thermometers are still on sale at Kroger, Medicine Shoppe, Publix and Fred's stores.

"It's appalling that there are retailers that continue to sell potentially dangerous mercury devices to their customers, especially when safe alternatives exist in the marketplace," says Jamie Harvie, mercury coordinator of HCWH.

Eight states and a number of cities have banned or restricted the sale of mercury thermometers, and 600 hospitals and clinics have agreed to get mercury out of their waste streams.

But mercury thermometers are only one, very visible part of the problem. Because mercury has many uses and applications, the movement to get it out of the atmosphere must take a multi-pronged approach. Some of the campaigns have made more headway than others, but all have acquired a new urgency as the dangers of mercury become better known.

Fish Filled With Mercury

According to a 2001 Centers for Disease Control and Prevention (CDC) study, one of 10 American women of childbearing age is at risk for having a baby born with neurological problems due to in utero mercury exposure. Statistically, that means 375,000 babies are at risk every year. Nearly six million women who might be considering having a child already have mercury levels above EPA safety guidelines.

As recounted in Morbidity and Mortality Weekly Report, the CDC study was based on a national survey of mercury in blood and hair, while previous studies were estimates based on per capita fish consumption.

"New studies show that far more women are at risk of exposure to methyl mercury than previously thought," says Caroline Smith DeWaal, director of food safety at the Center for Science in the Public Interest.

She urges the Food and Drug Administration (FDA) to monitor commercial seafood and to remove unsafe fish from the market.

A federal General Accounting Office (GAO) report, commissioned by Senator Tom Harkin (D-IA) in 1999, concludes that the FDA has failed in its efforts to protect the public from mercury-tainted seafood. The report faulted the FDA's Hazard Analysis Critical Point regulations for not providing proper guidance to the fishing industry about safeguarding the public.

A joint report by the Mercury Policy Project and California Communities Against Toxics in 2000 charged that the FDA had stopped mercury monitoring for tuna, shark and swordfish, despite the fact that the FDA's previous testing found more than one part per million (considered the "action level") of mercury in more than half the swordfish it evaluated. Some 33 percent of shark tissue studied by the FDA was found to exceed the action level for mercury, as was four percent of tuna. In 2001, the FDA finally recommended that women of childbearing age not eat shark, swordfish, king mackerel or tilefish. Tuna was not mentioned.

"The GAO report shows that mercury pollution threatens both sportfish and seafood," says Eric Uram of the Sierra Club's Midwestern office. "Consumers need to watch what fish they eat, no matter where it comes from -- the restaurant, store, lake or seashore."

A 2001 study that looked specifically at the New England states gave them a mixed report card for their efforts to reduce mercury levels in the environment, and warn the public about the risks. The New England Zero Mercury Campaign praised the states for developing health-based advisories about mercury in fish, but it urged them to do more to "effectively communicate these health warnings to women who may become pregnant and families with young children.Strategically targeted and culturally sensitive outreach and education is needed to prevent dangerous mercury exposure from fish, especially from commonly eaten seafood."

Prenatal mercury exposure, said the New England report, "can hurt children's ability to remember, pay attention, talk, draw, run and play, and increase the number of children who have trouble keeping up in school or require special education, according to the National Academy of Sciences." According to Dr. Ted Schettler of Physicians for Social Responsibility, "Relatively small amounts of contaminated fish eaten often, or larger amounts eaten occasionally, can harm developing fetal brains during windows of vulnerability. The fetus is extremely sensitive to mercury."

Switching Off Auto Mercury

What do the high-intensity headlights, anti-lock brake systems, global positioning screens and trunk- or hood-mounted light switches on your car have in common? They all may contain highly toxic mercury. The Clean Car Campaign, a coalition of several environmental groups, is trying to persuade the auto industry to not only stop all uses of mercury, but also to take responsibility for the heavy metal already installed in hundreds of millions of on-the-road vehicles.

The industry has agreed to phase out most uses of mercury switches by the end of the 2001 model year, but it is not surprisingly balking at the monumental effort needed to remove existing switches, many of which it says would prove difficult to locate. (At presstime, the state of Maine passed landmark legislation requiring carmakers to pay for a mercury auto switch recovery program that will take at least 90 pounds of the metal out of the environment every year.)

According to the Mercury Policy Project's Michael Bender, the auto industry installed 10 tons of mercury in car switches in 1995, although that amount was dramatically reduced by the 2001 model year. Mercury light switches are now used in only a few General Motors vehicles. Most European and Japanese auto manufacturers stopped installing mercury convenience light switches in the mid-1990s. But even as the switches are being phased out, many domestic and foreign companies are equipping their cars with headlights, brake components and navigational systems containing mercury.

The EPA, in a report to Congress in 1997, estimated that 158 tons of the metal are released into the atmosphere annually from manmade sources in the U.S.

"The auto industry is not the major source, but it's definitely a significant source," says Bender, who points to coal- fired power plants and waste combustors as the prime culprits nationally for mercury release.

Charles Griffith, the auto project director of Michigan's Ecology Center, a member of the Clean Car Campaign, says that the mercury in auto switches is released into the atmosphere when steel recovered from scrapped automobiles is melted down in electric arc furnaces (EAFs). A study produced jointly by the Ecology Center, the Buffalo-based Great Lakes United and the University of Tennessee Center for Clean Products and Clean Technologies estimates that 15.6 metric tons of mercury are released annually by EAFs, more than all other manufacturing sources combined.

Bob Kainz, a senior manager for pollution prevention and life cycle programs at DaimlerChrysler, says that only two of the company's 2001 products, the Jeep Cherokee and Wrangler, still had mercury switches in their ABS brake systems, and that both models will be free of the heavy metal when they're redesigned over the next few years.

"There are better ways of handling this problem than going after the carmakers," Kainz says. "Eighty-seven percent of the mercury going out into the atmosphere is coming from utility boilers, waste combustors, coal-fired power plants, cement plants and medical incinerators."

Kainz adds that DaimlerChrysler's records do not consistently identify which cars or trucks actually have mercury switches. The auto industry, through such trade groups as the Alliance of Automobile Manufacturers and the Association of International Automobile Manufacturers, has lobbied against the laws, arguing that it is phasing out mercury on its own.

Greg Dana, vice president for environmental affairs of the Alliance of Automobile Manufacturers, says that General Motors, Ford and DaimlerChrysler began removing mercury from their products in 1995 under an agreement with the state of Michigan. The mercury switches in existing cars, he says, should be removed when the car is at the end of its life.

"The recyclers are already taking out the gasoline, oil, and air-conditioner refrigerant," Dana says. "It's a simple add-on for them to rip out the mercury switches."

The auto trade groups support legislation requiring recyclers to remove the switches as part of the dismantling process, but this has produced a fierce reaction from junkyard operators and scrap steel dealers. Both the Automotive Recyclers Association (ARA) and the Institute of Scrap Recycling Industries say they have little financial incentive to take on the task, with each switch containing only a gram of the metal and mercury trading at less than $2 a pound.

According to ARA Vice President Bill Steinkuller, "The auto manufacturers engineered the vehicles to include mercury switches, produced the product and profited from it. From our point of view, it defies logic that they now want to deny any responsibility for the mercury and put the onus on the dismantlers."

The auto industry and the recyclers are fighting a war of words over mercury, but there is some chance of reconciliation.

"We're not trying to pick a fight with the manufacturers," Steinkuller says. "If we get beyond the rhetoric, we can probably get together and handle this problem."

Unfortunately, ARA's proposed solution -- in which the carmakers foot the bill for a nationwide program of mercury collection and storage -- is precisely the kind of high-cost program the auto industry is trying to avoid.

Chewing on Mercury

Anita Vasquez Tibau was a young college dance major 20 years ago when she suddenly found herself unable to breathe.

"I could hardly walk," she told Dr. L.A. McKeown in an article for WebMD Medical News. "I couldn't do anything. I was using my inhaler every half hour."

These problems plagued Tibau for 20 years until, in 2000, a blood test showed she was highly sensitive to mercury. After Tibau had a dentist remove all 13 of her mercury fillings, her health improved dramatically. She no longer uses any asthma medicine, and she reports much higher energy levels and an increased attention span.

The American Dental Association (ADA) reports that 76 percent of dentists use dental amalgam -- a mixture of metals, including silver, dissolved with mercury. The ADA denies that there are any safety problems with dental amalgam.

"Studies have failed to find any link between amalgam restorations and any medical disorder," the association says. But it concedes that "a very small number of people" are allergic to the fillings. "Fewer than 100 cases have ever been reported," says the ADA. "Symptoms of amalgam allergy are very similar to a typical skin allergy."

The ADA defended its position in court last year after Consumers for Dental Choice sued the ADA and the California Dental Association, claiming that both groups were misleading the public about the mercury content of what they call "silver fillings." But the ADA says it has never tried to hide the mercury connection.

A paper prepared by Consumers for Dental Choice and DAMS, another anti- amalgam advocacy group, charges that every amalgam filling releases 10 micrograms of mercury into the body daily, which is two-thirds of the excretable mercury level. The report also charges that mercury can cross the placental barrier into the tissue of a developing fetus, and it implicates the metal in kidney impairment, loss of immune function, antibiotic resistance and lowered fertility.

Boyd Haley, chairman of the chemistry department at the University of Kentucky, has been an expert witness before Congress on the mercury issue.

"They place this stuff in people's mouths and it's toxic before it goes in, and it's toxic when it is placed in your tooth, so how does it suddenly become safe?" Haley asks.

Many dentists, under pressure on the mercury issue, have switched to alternatives. According to Richard Epstein, a Connecticut-based dentist, "While I believe that the studies disparaging silver amalgam are seriously flawed, the alternatives are effective enough to warrant switching. I now use gold and composite materials."

Dentists have also been under fire for releasing unused amalgam into the waste stream, where it can enter the aquatic food chain. Some have invested in disposable amalgam traps, which catch the metal before it goes down the drain. Recaptured amalgam can be shipped to groups like Dental Recycling North America, which recovers 90 to 95 percent of the mercury in the fillings.

Congresswoman Diane Watson (D-CA) introduced legislation last year that would ban all mercury-based dental amalgam in five years. The New York State Dental Association has fought a proposed bill that would, among other things, require dentists to use mercury containment traps, file an annual amalgam report, and no longer use the fillings for pregnant or under-15-year-old patients. The association claims the legislation is "misguided" and "would detrimentally alter the practice of dentistry."

From the Smokestack

According to the National Academy of Sciences (NAS), dirty power plants, especially those that burn coal (which contains mercury naturally), are the single largest source of mercury emissions, resulting in an estimated 40 tons a year. Eighty-five percent of all mercury pollution in the U.S. is released either by coal plants or municipal and medical waste incinerators burning mercury-tainted trash. Only the incinerator emissions are regulated.

In 2000, a NAS report urged that mercury releases from power plants be drastically curtailed. Before leaving office, the Clinton Administration announced that it would develop new, stricter standards, to be proposed in 2003 and finalized in 2004. Then-EPA Administrator Carol Browner noted, "The greatest source of mercury emissions is power plants, and they have never been required to control these emissions before now."

Upon taking office, the Bush Administration signaled that it might reverse campaign promises about power plant carbon dioxide and mercury emissions. The move came after heavy industry pressure from the Utility Air Regulatory Group, which represents 50 large power plants.

Environmentalists loudly protested the administration's proposed reversal.

"Countless studies have documented that mercury emissions from U.S. sources, including coal-fired electric utilities, contaminate lakes and streams, the fish within those water bodies, and the people and wildlife who eat the fish," said National Wildlife Federation Senior Scientist Mike Murray.

In April 2001, the Bush Administration again changed course, attempting to quash an Edison Electric Institute lawsuit aimed at the Clinton-era mercury rules. Environmentalists were cautiously optimistic, but Bush's EPA is likely to phase in smaller mercury reductions over a longer period of time.

In model legislation created by the Mercury Policy Project, coal- burning electric utilities would be required to reduce their mercury releases 95 percent by 2008, but the Bush Administration is likely to impose a much weaker standard.

Groundbreaking legislation is instead coming from the states, including Vermont, which passed the Mercury Reduction Act in 1998. That bill requires manufacturers of "mercury-added" products to label them as such when sold to the public. The legislation also banned trash disposal of products containing mercury.

Vermont's bill prompted a lawsuit by fluorescent lamp manufacturers, who claimed an undue financial burden and argued that their First Amendment right not to disclose information had been violated. The lawsuit was later thrown out by two federal appeals courts.

Several other states intend to model legislation on Vermont's law. In 2001, Massachusetts unveiled strict new final standards for power plant emissions, becoming the first state in the nation to regulate mercury releases. The state's power plants will be required to phase in 50 to 75 percent nitrogen oxide and sulfur dioxide emission reductions by 2008.

"From a national perspective, this mandatory reduction of four major pollutants from the state's oldest and dirtiest power plants is a very important precedent," says Cindy Luppi, organizing director of Clean Water Action.

One final irony is that U.S. campaigners may be very successful in removing mercury from domestic commerce, only to see the deadly neurotoxin "recycled" to ready buyers overseas. That was exactly the case last year, when HoltraChem, a mercury-based chlor-alkali plant in Maine, shut down. Some 130 tons of mercury were sold to a broker, which resold it for use in India.

Madhumita Dutta, coordinator of the Indian group Toxics Link, calls this kind of transaction "toxic trade." Vehement protests in both India and the U.S. succeeded in at least temporarily stopping the deal, but there is an estimated 3.5 to five million pounds of mercury on-site at 11 other American chlor-alkali plants.

For environmentalists, the battle against mercury has many fronts. It's not just in thermometers, but also in pharmaceutical products and vaccines (in the form of thimerosal, a preservative), and it is in car parts, too. As soon as legislation is passed to take it out of some consumer products, it pops up in others.

A worrisome new use is in high-tech gadgetry, like global positioning screens and high-density auto headlights. Mercury pours out of smokestacks and arc furnaces and, according to the National Center for Atmospheric Research, tons of it (stored in foliage and ground litter) goes up in smoke during wildfires. It's an elusive enemy, but one well worth fighting.