You, the family health fanatic, heed the American Heart Association’s recommendation to eat omega-3 fatty acid-rich fish twice a week. You take yourself and your family to the dentist twice a year, and you eat organic food. Despite your good care, you feel fatigued, foggy-headed, and irritable. You can’t remember where you left your car keys—or your car. You may have a family member with Alzheimer’s. If this sounds familiar, do yourself a favor and get your hair or blood tested for mercury.
Aside from uranium, mercury is the most toxic metal known to man; it takes only a few milligrams to kill you, and once it accumulates in your tissues, it can cause neurological problems and organ damage. Mercury toxicity in humans has been linked to chronic fatigue syndrome, cardiovascular disease, and kidney problems, and some believe it’s responsible for the alarming rise in autism and Alzheimer’s disease.
“We have a very serious problem here,” said Dr. Boyd Haley during a September 2006 clinical teleconference. Haley is chairman of the chemistry department at University of Kentucky, and he has conducted extensive research on mercury’s effects on brain and nerve tissue. “Every study of mercury on the human brain shows that it generates neuronal problems,” he said. “The American Dental Association (ADA) and the FDA ignore this, saying mercury is safe and has no effect on the brain. This is 100 percent wrong.”
Mercury compounds can enter the body through various pathways, including inhalation of vapor, ingestion, and skin contact. It’s found in paints, pesticides, batteries, fluorescent light bulbs, skin creams, vaccines, old-style thermometers, eye drops, and of course, those silver amalgam fillings in your mouth. Despite the American Dental Association’s best efforts to downplay the risk, mercury from amalgams is continually released, increasing as you chew food or gum. “Mercury comes off amalgam fillings at a rate much, much higher than the ADA spokespeople say it does,” says Haley. “Eighty percent that comes off the fillings is retained by the body.”
After ingestion, mercury binds with proteins and amino acids and is transported freely throughout the body, accumulating in tissues and crossing the blood-brain membrane barrier, which normally prevents toxins from entering the brain. Mercury and other heavy metals have the ability to pass through this semi-permeable barrier, where they become stored in the brain, wreaking havoc on the central nervous system. Over time, mercury leads to oxidative damage (think of a bicycle rusting inside your body), mitochondrial dysfunction (Remember high school biology? Mitochondria are cellular power generators, which explains why mercury toxicity causes fatigue), and eventually, cell death.
An element of the earth’s crust, mercury comes to us in three main forms. Elemental mercury, or quicksilver, is the shiny, slippery metal many of us remember from the dentist’s chair. Liquid at room temperature, it is used in thermometers and batteries as well as fillings. Inorganic mercury is used in fungicides, antiseptics, and some Chinese herbal medicines. Organic mercury is created when inorganic mercury combines with carbon. Burning coal, for instance, releases mercury particulates into the air, where they settle into bodies of water and are converted by microscopic organisms into methylmercury, the most common organic mercury compound in the environment. This is the kind found in fish; it accumulates up the food chain.
Says Caryn Mandelbaum, environmental health analyst at Marin’s Got Mercury?, a project of the Turtle Island Restoration Network (TIRN), “Now we’re seeing mercury levels higher than what the EPA is regulating. Mercury began to rise with the Industrial Revolution, so after a couple of centuries of industrialized factories, coal-burning plants, and crude oil, there are questions about what percent is man-made, but figures range up to 70 percent.” This is especially troubling because the most harmful forms of mercury have great staying power. Once it accumulates in the environment, Mandelbaum says she’s not aware of any method to remove it.
And the deadliest are organic mercury compounds. It takes only drops of a certain organic mercury compound to cause death. Methylmercury is the most stable (it remains stored in body tissues and is very difficult to excrete) and most easily absorbed by the body. From bacteria to plankton to herbivorous fish to predatory fish, it bio-accumulates, and in each species, the concentration increases. Humans receive the highest hit when they consume larger, predatory fish such as tuna, shark, or king mackerel. So how risky is it to eat fish these days?
“We’ve always known about heavy metals in the high seas,” says Mandelbaum. “But in the early ’90s, we saw a big consumer shift, a health consciousness to increase seafood in diets, and it became more apparent to us that this heightened consumption was bringing mercury into the food supply. By 2000, the diet industry was pushing tuna as the principal protein source to young girls and teens to keep their weights down. Also, sushi became really big, so these shifts were putting consumers at risk. TIRN decided the government wasn’t doing enough to raise awareness about the toxic effects of mercury in the food supply.” As a result, TIRN formed Got Mercury? to protect the environment and educate the public about the dangers of mercury.
Back in 1979, the FDA set action levels at one part per million as a safe level of mercury in fish, “but you may as well call them inaction levels,” says Mandlebaum, “because, to this date, the FDA hasn’t done anything to remove fish with really high mercury levels from stores. Got Mercury? has been pushing for all kinds of consumer awareness, including putting signs up in stores.”
Mandelbaum and her group began testing several years ago and found high mercury levels in seafood. “We started our campaign presenting swordfish as a dangerous fish due to the high mercury content. It’s one of the bigger fish in the sea, and the typical rule of thumb is the larger the fish, the more mercury.” California state officials now warn against eating fish from areas around the Delta, the San Joaquin River, and San Francisco Bay, which contains over 3,500 pounds of mercury, according to a recent study.
“Around 2003, the same time we were seeing really high levels in fish, there were medical reports coming out about women with mercury contamination in the Bay Area,” Mandelbaum notes. A Marin physician noticed recurring symptoms in her patients—fatigue, loss of motor skills, and loss of concentration—and she began testing for mercury. Out of 720 surveyed patients, she found 140 with mercury levels and exposure far higher than the levels set by the EPA.
In 2004, Got Mercury? lost a suit to have warning labels posted around shelves stocking canned tuna. The FDA intervened, stating the tuna industry could not be held accountable for mercury in tuna. “The FDA argues that 99 percent of mercury is naturally occurring,” Mandelbaum says, “but we’re seeing amounts in the tons emitted per year and falling into the sea. We think the FDA is under-reporting the threats of mercury in canned tuna because of commercial ties with the tuna industry.” These ties include USDA programs that supply canned tuna to the National School Lunch program, to Native Americans, to the Supplemental Nutrition Program for Women, Infants and Children (WIC), and to families in need.
Despite setbacks, Got Mercury? continues to pressure Bay Area supermarkets to post signs alerting consumers to the dangers associated with mercury and fish consumption. To date, only Andronico’s has posted warnings that children and pregnant and nursing mothers should not consume swordfish, shark, king mackerel, and tilefish. Mandelbaum says, “The Right to Know Law says consumers have a right to be informed about carcinogenic materials in their products and foods, and we’ll continue pushing the supermarkets to inform customers about how to protect their health. If only consumers had more knowledge to choose wisely, they could maintain healthy diets.”
Mandelbaum hopes that someday fish will be tested for mercury before it lands in supermarkets. “Just last March, the Canadian health department implemented a ban on any fish that has mercury levels greater than one part per million,” she says. “Now they’re doing random testing because ultimately, if you have an epidemic of mercury contamination with a population facing lower IQs, potential heart failure, and low motor function, that will cost the Health Department a whole lot more than taking some fish off the shelves.” In the meantime, Got Mercury? advises against eating more than six ounces of fish weekly and cautions against consuming high-risk fish. Switching to farmed fish is not without risk, as it can contain high levels of PCBs and other chemicals. Ultimately, Mandelbaum says, “We encourage shifting consumption to other sources of protein.” To calculate your mercury exposure based on how much fish you consume, go to www.gotmercury.org.
Pregnant women and their fetuses are at highest risk for mercury toxicity, because mercury travels easily across the placenta and becomes concentrated in developing fetal tissues, especially in the brain and liver. Pregnant women are cautioned against consuming swordfish and other mercury-tainted varieties. According to a 2004 estimate, one in every six women of childbearing age has enough mercury in her body to pose a risk to her child, and studies indicate that the developing fetus may have more difficulty excreting mercury than its mother. Many studies link mercury to the increase in autism and other developmental disorders.
Haley points out that the first case of Alzheimer’s on record occurred in 1903—50 years after dentists began using amalgam fillings. “The number one source of mercury exposure in our country is amalgam fillings,” says Dr. Kurt Woeller, an osteopathic physician in Temecula. Eighty-five percent of Woeller’s practice deals with children on the autistic spectrum; he believes autism is due in part to high levels of mercury and other heavy metals. “For most neurological conditions, mercury is one of the most under-diagnosed or under-recognized potential triggers, and it is so prevalent in our environment. The medical community has a good foundation for something like lead poisoning, but it’s amazing that when it comes to mercury poisoning, everyone turns a blind eye.”
Over three-quarters of adults have mouths full of amalgams. “There is no doubt, especially if you have a family history of neurological problems, that amalgams should be removed,” recommends Haley. Woeller is also an advocate for amalgam removal, especially for women thinking of becoming pregnant. Both say to use caution in selecting a dentist: dentists need to have proper training in safe amalgam removal.
How difficult is it to remove mercury from the body? “When it comes to treatment, we use chelation therapy,” says Woeller. Chelation therapy uses a chelating agent such as DMSA, a chemical compound that can cross the blood-brain barrier, to remove mercury from brain and body tissue. It has long been the standard of care treatment in both the conventional and alternative medical communities. “It’s controversial, but it’s medically necessary. There’s no other way to get this stuff out,” Woeller says.
In regards to limiting mercury exposure, Woeller says, “None of us lives in a bubble, so we’re not going to be able to avoid mercury 100 percent.” He advises directing attention to a clean living environment. “There are ways to decrease exposure. Limit high-risk fish consumption; get rid of sugar and junk food and incorporate whole, organic foods; never get amalgam fillings, and avoid thimerosal-containing vaccines. Hook up home air and water filtration systems, and check your products,” he advises. Visit www.fda.gov/cder/fdama/mercury300.htm for an updated list of mercury-containing drugs and products.
There is also legislation in the works to curb mercury emissions. “Senators Lisa Murkowski from Alaska and Barack Obama have sponsored a piece of legislation called the Mercury Minimization Act, calling for a ban on elemental mercury exports by 2011,” Mandelbaum says. “They recognize that mercury contamination has really detrimental effects on health and will cost societies a lot more than preventive measures.”
Says Woeller, “We have a metal that significantly impacts the nervous system, so it not only affects one’s ability to focus, but it can impact a person’s ability to communicate, to function, and it can cause violent behavior. Just the financial aspects alone to take care of autistic kids, especially in the school system and from a pubic health perspective—it has a huge impact socially and financially.”