Mercury toxicity: risk, symptoms, and how to check if you are affected by mercury poisoning.

Heavy metal toxicity or poisoning arises when the body accumulates an excessive amount of a heavy metal, such as mercury, lead, arsenic, cadmium, aluminium or nickel which places the individual at risk for serious illness.

These heavy metals play no known biological role in the human body, unlike with some elements such as selenium, which is an effective antioxidant, iron, which is required by blood cells, and copper, which is an integral part of many enzymes. Since they are not useful to the organism, and because the body has storage sites for them, these heavy metals can accumulate in tissues over time and cause serious health problems.

Toxicity from mercury, in common with the other heavy metals, arises from environmental contamination and also from some unexpected sources as we shall see below. With mercury, it is the nature of the environmental sources that are particularly worrying in the context of nutrition.

Main Sources of mercury toxicity/poisoning:

• Drinking contaminated water
• Eating fish contaminated with mercury
• Leaching of mercury from badly fitting dental fillings.
• From vaccinations containing thimerosal.

It has been estimated that the ordinary American is exposed to tap water containing heavy metals at levels exceeding the safe upper limit. With lead, for example, it is estimated that 40 million Americans drink water containing levels exceeding the safe limit set by the EPA. The lead contamination comes mainly from lead plumbing in older homes and soldered joints in copper pipes.

Other heavy metal found in tap water include copper and arsenic. Copper serves as a co-factor for many enzymes and is required in the diet in small amounts for normal health. However, high doses of copper is dangerous to health. A single dose of 15 mg copper can cause nausea, vomiting, diarrhea and abdominal pain. More severe toxicity can cause liver and kidney damage.

The copper in tap water comes from corrosion of copper pipes and can accumulate overnight. In this case flushing the tap before using the water is highly recommended.

Arsenic has been found in tap water in levels substantially exceeding the EPA safe limit in several areas of the country. For example, earlier this year a US Department of Health investigation found high levels of arsenic in tap water samples in Churchill County, Nevada, and In Iowa, several public water supplies were found in mid 2001 to have high arsenic levels. Because of the risks of cancer from arsenic levels below the current limit of 50 parts per billion, the EPA has set new standards of 10 ppb to take effect in 2006.

Mercury from environmental contamination (derived mainly from coal-fired power plants and medical and municipal incinerators) eventually enter our water system through soil, rivers, streams and lakes. The form of mercury hazardous in drinking water is the inorganic form, which can easily be converted to the organic form, methylmercury, by bacterial action present in soil and water environments. As discussed below this is the form that eventually enters our food chain.

The maximum level of mercury in drinking water permitted by the EPA is 2 parts per billion. Although levels of mercury in tap water are generally within this limit, there have been reports of mercury exceeding the EPA safe limit in several areas of the country, most notably from well sources. In New Jersey, for example, a survey found 265 out of 2,239 wells with high mercury levels.

Toxicity from eating contaminated fish: This is one of the main sources of mercury poisoning and one which is attracting a great deal of recent attention.

The FDA is coming under increasing pressure from environmental groups to warn the public of the dangers of eating tuna because it contains enough mercury to damage a developing foetus.

This is one of the most topical issues on mercury toxicity. It is one that is steadily gaining public awareness ever since the link between autism and vaccinations was first proposed. A little known fact before public awareness campaigns started is the fact that the preservative, thimerosal usually added to vaccines contain mercury. In 1999, the Centers for Disease Control and prevention (CDC) called for the removal of mercury from vaccines. Paradoxically, the CDC still continues to recommend the measles, mumps and rubella vaccine.

Thimerosal structure

Long-term toxic exposure can also lead to infertility in men and women. Toxicity also affects pregnancy outcome and has also been linked with cardiovascular disease. In a study of over 2000 men, high hair mercury content was linked with an increased risk for heart disease and stroke.

In the young, mercury toxicity usually leads to childhood learning disability (see above discussion on autism).

However, bear in mind that none of the above symptoms is unique to mercury toxicity and may arise by other causes. Therefore, the only way to tell if you have accumulated a toxic amount of mercury is not by symptomatology alone, but by having a mercury test done.

Tests for mercury toxicity and other heavy metal toxicity/poisoning:

Of the tests available, the hair test, referred to as hair mineral analysis, is by far the easiest and most powerful diagnostic test for heavy metal toxicity that you can have done. The hair mineral analysis is used by many health professionals, including many in the alternative medicine field, to check for mineral imbalances and deficiencies as well as for mercury poisoning and heavy metal toxicity. It has received much attention in this regard, and there are some limitations of the analysis largely with variations in results between labs, but overall it offers an accurate and convenient method to check for the presence of heavy metal toxicity. The remarkable thing about the hair analysis is the convenience and ability to give information not only on mercury, but on all the other heavy metals as well. So, if you have any other heavy metal toxicity, such as lead toxicity, cadmium toxicity, arsenic toxicity, aluminium toxicity, barium toxicity or nickel toxicity, you will discover this with the test.

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Hair is used to determine mercury toxicity because hair accumulates heavy metals (as well as essential minerals) in concentrations 1000-times more than other biological tissue. Numerous scientific studies attest to the usefulness of hair analysis as a test for heavy metal toxicity. One doctor, who testified before the committee on Government reform on the association between mercury toxicity and autism, routinely uses hair analysis in her family practice which treats hundreds of autistic cases every year.

The other types of tests used for checking for mercury toxicity differ in the source of the biological sample used for testing: blood, urine or saliva. Each has its limitations.