Mercury at very low doses may be harmful to one person but not to another. As I mentioned before, there is at least a thousandfold difference in individual thresholds for mercury poisoning; one researcher has measured differences of one millionfold. Knowing how much mercury it takes to poison the average person is of very little help when the average is somewhere within a range that starts at one and goes to one million. No one knows where to (ADM' the line between what we call mercury poisoning and mercury sensitivity. This situation is quite unlike any other toxin or allergen. Emily's exposure [previous case history presented in the book], illness, and treatment are difficult to translate into yours because your sensitivity to mercury may be many times higher or lower. If your sensitivity is higher, then you must at least be conscious of mercury as a possibility. Your specific symptoms are not a very good trigger for thinking about mercury because a list of symptoms for low-level mercury toxicity covers just about any complaint you could name. The rule to remember from Emily's story is that you have to think about mercury before doing something about it. The lesson I learned from treating Emily to remove the large amounts of mercury that remained in her body more than forty years after her exposure was that it was not too late to relieve many of her symptoms: fatigue, eczema, irritable bowel, acid reflux, and intermittent urinary urgency and pain.
No one knows exactly how variability in mercury sensitivity works, considering that its range exceeds other differences between people. Surely, one factor is a basic quirk in the biochemistry of sulfur, an element that accounts for much of the stickiness needed to put things together as well as to detoxify, which, you will remember, involves putting good molecules together with toxic molecules for the sake of ushering toxic ones safely from the body. You may recall a news story about a professor at Dartmouth College who died months after touching a particularly toxic form of mercury. She touched only a tiny drop and did so wearing a rubber glove. Her long illness and death must have come about because of a quirk in her ability to detoxify mercury and a domino effect within her chemistry, in which the toxicity was magnified rather than minimized over time as would usually be the case.
Not knowing how sensitive any given person may be is just one of many factors that complicates the question of mercury:
There is no completely decisive test to find out how much mercury is stored in your body. Mercury levels in hair are a somewhat reliable indicator. A urine sample after taking dimercaptosuccinic acid (DMSA), a chelating drug, is another test that will be discussed below. (Chelating medicines—named from the Greek word for a "claw"—grab, or bind. heavy metals to neutralize and remove them.)
There is no decisive test to determine your individual tolerance to mercury or what problems any particular dose may cause after exposure at any given moment in your development or in combination with other toxins. There are, however, no tests of mercury toxicity that give us an idea of the dangers of low-level exposure. Richard Deth, Ph.D., has shown paralysis of one of chemistry's most important steps" by levels of Thimerosal that are one hundred times lower than what can be measured in babies a couple of weeks following a single Thimerosal-containing immunization.'
The chelating medicines that pull mercury from your body or support your body's chemistry for detoxifying mercury may produce beneficial effects independent of any role they may have in removing mercury.
One of the most puzzling factors is a rinsing paradox. When I wash my socks, most of the soap and dirt comes out with the first rinse. Each subsequent rinse produces less dirt until the socks come out clean. Never in washing my socks has the dirt stayed in them until the fourth rinse and then suddenly come pouring out. But something like this appears to happen in some people when they take repeated pulses of DMSA after failing to release much mercury into their urine after the first, second, or third three-day course of treatment.
Symptoms of mercury toxicity fall within the realm of every medical specialty (pediatrics, internal medicine, family practice, dermatology, neurology, gynecology, etc.). But most regular specialists visited by patients for possible mercury-related symptoms are not usually aware of mercury as a potential factor.
Many practicing physicians remember giving mercury-containing medications with the understanding that the toxicity of such medication was tolerable. This indifference to The re-methylation of homocysteine (sec page 143). the possible negative effects of mercury goes to some amazing extremes, including the use of mercury-containing thermometers, which if spilled could contaminate a household with what nowadays are considered dangerous amounts of mercury vapor.
Drug companies and the FDA have permitted the use of mercury-containing preservatives in eyedrops as well as in immunizations injected into babies. The American Dental Association advocates the use of mercury containing fillings, insisting on their safety and actively persecuting dentists who point out the dangers. These pro-mercury forces, combined with the medical profession's long history of using mercury as a medicine, slow down the spread of information that would lead most of us to avoid mercury until scientific methods are developed to determine individual tolerances for it.
Fish is a significant source of mercury exposure. Mercury in seawater is passed up the food chain to the big fish, such as tuna. The microorganisms that take mercury from the water and pass it on to the tiny fish that eat them are also the originators of the good oils that are so important to correcting the lack of omega-3 fatty acids in our diets. Eat less fish and you get less good oil, but you are spared the burden of mercury. I resolve this dilemma by limiting my intake of fish, avoiding tuna and other large fish, and by taking my fish oil as a supplement, after making sure that the supplement is free of mercury, dioxins, and PCBs (polychlorinated biphenyls).
Mercury's toxicity varies considerably among its different forms, with metallic mercury (quicksilver) causing little absorption when touched or swallowed, while mercury vapor and organic forms of mercury (methylmercury found in fish; ethylmercury found in Thimerosal, used as a preservative in vaccines and eyedrops) are nearly completely absorbed.
Mercury raises some tough questions, especially for those involved in the formation of public policy. It is one thing to protect the public from some new danger by requiring extensive studies of safety and effectiveness. It is another thing altogether to abolish practices that have been assumed, without carefully conducted studies, to be safe, but for which there is mounting evidence of danger. The difficulty of changing public policy is magnified when it involves the utterance of that forbidden medical word: "oops.- Even when health professionals may be prepared to base new public policy on changing assessments
of the risks of, say, dental amalgam, their lawyers may point to exposure to liability suits based on questions about what they knew and when they knew it, and further delay action.
Still, you don't have to make public policy; you have only to decide what is right for yourself and your family. Here are some steps I think you should consider. These steps are subject to revision! My own thinking about mercury has changed slowly over the last twenty years as I became more attentive to the work of colleagues, the experience of my patients, and the evolving scientific literature.'
1.Get your silver-mercury amalgam dental fillings replaced. Using the word amalgam for a Web search will bring you a list of sites providing both sides of this highly polarized debate on the dangers of mercury-containing fillings. At www.amalgam.org you will find information provided by DAMS (Dental Amalgam Mercury Syndrome) Inc., along with Consumers for Dental Choice, A Project of the National Institute for Science, Law and Public Policy, 1424 16th Street, NW, Suite 105, Washington, DC 20036. Included are protocols for dentists for safe amalgam removal provided by the International Academy of Oral Medicine and Toxicology (IAOMT).
2. Stop eating fish that contain high levels of mercury. Seafood contains more mercury than any other food. There is naturally occurring mercury in the oceans, but this is a tiny fraction compared to what has been added by human contamination. When people dispose of mercury, it finds its way to the sea. One study of dietary mercury intake gave a daily average of 1.3 mcg for the general population of the United States and 3.1 mcg for people living in New jersey who ate fish. The range of intake was up to about seven times the average in people who ate more fish. Mercury levels in various seafood products may vary considerably depending on their source location. Dr. Jon Pangborn conducted an informal study and found oysters, clams, and mussels were highest. Scallops and shrimp were high but ,irk: quite variable depending on the location. Shark and tuna were high (hut tuna packed in water had little compared with tuna packed in oil). Seaweed can be the worst depending on location. Seaweed foods in a Japanese restaurant call he OK, but seaweed from Tampa Bay was ten to twenty times higher in mercury content than were the oysters off Sanibel Island. As a general rule, fish large enough to provide steaks come from predators at the top of the food chain where mercury becomes concentrated in the flesh of fish that have eaten the medium-size fish that have eaten the little fish that have eaten the tiny fish and vegetation. The smaller the fish, the lower the mercury content.
3.Once your teeth are mercury-free, have a urine test to see how much mercury comes out in your urine on the third day of taking a substance (DMSA, also called succimer; a pharmaceutical brand is Chemet) that draws mercury from your tissues into your urine. Such a test can be obtained from Great Smokies Diagnostic Laboratory (63 Zillicoa Street, Asheville, NC 28801-1074; Phone 800-522-4762) or Doctor's Data Laboratory (170 W. Roosevelt Road, West Chicago, IL 60185; Phone 800-323-2784; 708-231-3649). Both labs can provide you and your health-care provider with the details needed to carry out and interpret the test.
4.Depending on how you feel during and after your three-day dose of DMSA, and on the results of your urine test, consider taking DMSA along with a variety of supplements until either your urine levels fall to a minimum or you have a substantial improvement in symptoms. Here is a regimen you and your physician can follow for taking DMSA and the supplements. It is adapted from the regimen for mercury detoxification or oxidative therapy from the DAN! (Defeat Autism Now!) Mercury Detoxification Consensus Group Position Paper (May 2001, James Laidler,
