Heavy metals are a well-known cause of environmental pollution and of serious hazard to human health. The effects of their actions are not immediate, but show up after many years or decades. Due to their wide usage in many industrial branches they are present everywhere in the air, water and soil. Food contaminant by heavy elements is hard to avoid and it is a result of environmental contamination by dusts, industrial gases, sewage, waste and coal burning processes. The content of heavy metals in the environment is quite diverse and their harmful action depends on the type of element, the chemical form of their occurrence and the state of organism's nutrition. One of the very toxic and also very frequently used heavy metal is mercury. Exposure to mercury can cause immune, sensory, neurological, motor and behavioral dysfunctions.
   Fish consumption is a main source of mercury intake by Americans. Mercury finds itself into waterways, mostly through the burning of fossil fuels like coal, where bacteria convert it to toxic methyl mercury. Small fish eat or absorb methyl mercury, which becomes more concentrated as it moves up the food chain into large predatory fish. Mercury binds to the meat and cannot be removed from fish by cooking or removing the fat.

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Mercury in Sushi
Sushi is more popular than ever, but eating sushi may expose us to a higher level of mercury than we may realize. In January of 2006, Eli Saddler of gotmercury.org, a campaign of California-based Sea Turtle Restoration Project, went to six top sushi restaurants in Los Angeles to test the mercury levels in the fish they serve. The tuna samples from the six popular sushi restaurants in Los Angeles were taken to a Southern California lab for testing. The samples had an average mercury level of 0.721 parts per million, about 88 percent higher than the Food and Drug Administration maximum level of 0.383 ppm for fresh and frozen tuna. Big-eyed tuna and blue and yellow-finned tuna are the most popular varieties used in sushi restaurants. Older and bigger fish are considered best suited for sushi but Saddler said it was not widely known that fish with longer lives carry more mercury than others. Studies show seafood like shrimp and salmon with short life spans pose almost no risk of carrying mercury. Long-living, large predatory fish like tuna are the most likely to have mercury contamination.
     Dr. Sahelian comments: Unless you are eating a large amount of sushi on a regular basis, I don't think you need to be concerned. Just eat less tuna sushi and have a variety of different fish.

Mercury in Tuna and Fish
In May 2006, San Francisco Superior Court Judge Robert Dondero ruled that tuna companies do not have to put labels on their cans warning the fish contains mercury. The lawsuit was brought by California's attorney general Bill Lockyer, who in 2004 sought to ban the sale of canned tuna without mercury warnings. Lockyer sued Del Monte Foods, maker of StarKist tuna; Bumble Bee Seafoods, a unit of Connors Brothers Income Fund of Canada, maker of Bumble Bee tuna; and Tri-Union Seafoods, maker of Chicken of the Sea tuna. The complaint alleged the firms violated state Proposition 65, an initiative approved by voters in 1986 to require firms to issue warnings before exposing people to "known carcinogens or reproductive toxins." Although most  fish contain trace amounts of mercury, some species, such as tuna and swordfish, can have higher levels.
   Tilapia and trout have low mercury levels, as do shrimp, crab and scallops. Both farmed and wild salmon are low in mercury and high in essential omega-3 fats. As well, fish oil supplements are a safe way to get omega-3 fatty acids because they are generally made from smaller fish like sardines and anchovies.

Mercury Dental Filings
August 2006 - Two long-awaited, government-funded studies found no evidence that dental fillings containing mercury can cause IQ-lowering brain damage or other neurological problems in children. Children with such fillings were no more likely than other youngsters to suffer such problems. The studies are unlikely to end the fierce debate over the long-term effects of what are known as amalgam fillings. Amalgam fillings, also called silver fillings, are made of mercury and other metals and have been used by dentists for more than a century. But their use has dropped in recent years as more and more doctors switch to resin composite fillings, which are considered more appealing because they are white.

September 2006 - Government health advisers rejected a federal report that concluded the mercury-laden amalgam that dentists use to fill cavities was safe, saying further study was needed. A panel of Food and Drug Administration advisers did not declare silver fillings were unsafe. But in a 13-7 vote Thursday, the advisers said a federal report didn’t objectively and clearly present the current state of knowledge about the fillings. In a second 13-7 vote, the panelists said the report’s conclusions about safety weren’t reasonable.

June 2008 - Mercury fillings may cause health problems in pregnant women, children and fetuses, the Food and Drug Administration has admitted. Millions of Americans have the fillings, or amalgams, to patch cavities in their teeth. "Dental amalgams contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses," the FDA said on its Web site. "Pregnant women and persons who may have a health condition that makes them more sensitive to mercury exposure, including individuals with existing high levels of mercury, should not avoid seeking dental care, but should discuss options with their health practitioner," the agency said. Mercury has been linked to brain and kidney damage at certain levels. Amalgams contain half mercury and half a combination of other metals. Only 30 percent of fillings given to patients were mercury-filled ones as of 2003, according to the American Dental Association (ADA). Other options include glass cement and porcelain as well as other metals such as gold, but they cost more and are less durable.

Mercury Dental Filings controversy continues - Sept 2006
Food and Drug Administration reviewed 34 recent research studies and found "no significant new information" that would change its determination that mercury -based fillings don't harm patients, except in rare cases where they have allergic reactions. Consumer groups opposed to the use of mercury for dental filings disputed the FDA's conclusions. The groups plan to petition the agency for an immediate ban on use of mercury dental filings in pregnant women. Amalgam fillings, also called silver fillings, by weight are about 50 percent mercury, joined with silver, copper and tin. Dentists have used amalgam to fill cavities since the 1800s. Today, tens of millions of Americans receive mercury fillings each year. Amalgam use has begun to decline, however, with many doctors switching to resin composite fillings, considered more appealing since they blend better with the natural coloring of teeth. With amalgam fillings, mercury vapor is released through tooth-brushing and chewing. In general, significant levels of mercury exposure can permanently damage the brain and kidneys. Fetuses and children are especially sensitive to its harmful effects. Scientists have found that mercury levels in the blood, urine and body tissues rise the more mercury fillings a person has. "If substantial scientific evidence showed that dental amalgam posed a threat to the health of dental patients, we would advise dentists to stop using it. But the best and latest available scientific evidence indicates that dental amalgam is safe," said Dr. Ronald Zentz, senior director of the American Dental Association's council on scientific affairs. Rep. Diane Watson, D-California., who has introduced legislation that would effectively ban the use of mercury in dental fillings by 2008. Watson will press the FDA for a ban and call on the agency to study the environmental impact of dental mercury. Also on the legislative front, Sen. Mike Enzi, R-Wyoming., and other Senate colleagues have asked President Bush's nominee to head the FDA about the safety of mercury fillings.

Mercury Questions
Q. Are there any herbs or antioxidants such as lipoic acid, acetylcarnitine, or dmae that can neutralize mercury toxicity?
   A. I have not come such research at this time. It's possible many do, I just have not seen specific research.

Q. Should women avoid eating canned tuna? According to Consumer Reports, this is what they say, "Pregnant women should not eat canned tuna because it may contain harmful levels of mercury."
   A. Government tests found instances where canned light tuna had as much mercury, a potentially harmful heavy metal, as white tuna, also known as albacore. High levels of mercury in the bloodstream may harm developing nervous systems, according to the Food and Drug Administration. Fish and shellfish are the main sources of mercury exposure for humans. However, I don't think one needs to completely avoid canned tuna. One or two cans a month should be perfectly okay.