Mercury is a very dangerous poison. Basically, there are three forms of mercury: metallic, inorganic and organic. Although there is considerable debate as to which form is the most harmful, there is abundant evidence that indicates the inorganic form (also called ionic mercury) is the most dangerous. Ionic mercury is also the most difficult to remove from the body and in particular from the brain. Fortunately, few people are exposed to ionic mercury directly - most exposure is indirect. Unfortunately, a number of studies have shown that the other two forms are converted into ionic mercury within the tissues, especially in the brain. Therefore, any and all mercury exposure should be regarded as basically having the same potential.

Many people have suffered and died from mercury poisoning. The following are two incidents of mercury poisoning that gained the attention of the media:

* Mercury was dumped into Minamata bay in Japan from 1932-1968. Over 5,000 people suffered from mercury poisoning and 456 died. Children were born severely deformed and mentally retarded.

* In 1971 50,000 people in Iraq were poisoned and 5,000 died after they ate bread contaminated with mercury.

Although these were dramatic and tragic events the largest sources of mercury poisoning are:

* Dental fillings

* Contaminated fish

* Vaccines

* House paint

Almost 50% of dental fillings are the metallic form of mercury. The American Dental Society, until just recently, covered up the evidence that the mercury was released in vapor form and that 80% of that mercury vapor was absorbed into the body. Several studies have shown that blood levels of mercury rise several times when people with amalgam fillings chew or drink hot liquids. This is significant. Consider that in 1990, the EPA outlawed the use of mercury-filled interior latex paint because studies found that people living in houses covered in this paint had dangerously high mercury levels in their bodies. The Occupational Safety and Health Administration (OSHA) set the safety limit of mercury in the air at 50 ug per cubic meter (50 ug/m3). Measurements of the air in the mouths of people with numerous amalgam fillings have exceeded this level (reaching as high as150 ug/m3). This has particular implications for pregnant and breast feeding women.

Fish and other seafood are contaminated by waste from coal burning furnaces and pesticides and herbicides containing mercury. The sea floor also produces natural sources of mercury. As a result, a large number of previously safe seafood are contaminated with mercury. The mercury enters all sea creatures, but some are more toxic than others. Fish that eat other fish have the highest levels and in general the larger the fish, the higher the concentration. Certain fish should never be eaten, because of their extremely high methylmercury levels. These include:

* shark,

* swordfish,

* king mackerel and

* tilefish.

Select fish and other seafood that are low in mercury, such as salmon (from the Pacific) or pollock, or shrimp. However, Gulf shrimp is contaminated with a number of industrial chemicals as well as mercury, especially since Hurricane Katrina. Although most vaccines had their mercury removed as of 2001, the flu vaccines and the Rho immune globulin vaccine still contain mercury. Vaccines contain a special form of mercury called ethylmercury, which is found within the preservative and antiseptic thimerosal. Recent studies have examined ethylmercury and found that in fact it is much more toxic than methylmercury (the form found in fish). In the brain it is readily converted to the more toxic mercury ion. Vaccines containing mercury are strongly link to autism.

Toxic Effects of Mercury

Mercury is fat soluble and it accumulates in fat containing tissues such as the brain, heart, kidneys and liver. It reacts with a number of important structures and chemicals in the organs. Mercury concentrates in cell nucleus, and in even low doses it can cause damage to DNA. Damaged DNA can lead to cancer and degenerative brain disease. Changes, or damage, to DNA can be passed on to subsequent generations, so any children you have after the damage can inherit the problem or risk it produces.

The heart is especially sensitive to mercury toxicity. One study of people with an often fatal disorder called idiopathic cardiomyopathy found that their heart muscle contained a level of mercury that was 22,000 times higher than that seen in hearts of other people the same age. This disorder causes heart failure and people with the problem can require a heart transplant. The elderly with pre-existing heart disease, who receive yearly flu vaccines, are particularly at risk as the flu vaccines still contain mercury.

The brain is another organ that is particularly sensitive to the accumulation of mercury. Most of us have heard the old saying mad as a hatter. This saying originated from the felt hat industry during the 17th through the 19th centuries. It was commonly observed that people who worked in the industry walked as if they were drunk. They were also quite irritable and exhibited bizarre behavior. It was discovered that a form of mercury used in the manufacture of felt hats was to blame.

Mercury can alter how the brain functions, particularly the memory, concentration, motor control and behavior. Depression, memory loss, moodiness, irritability, a lack of interest in events, a desire to be alone, shyness and outbursts of anger are all signs of mercury poisoning. Low doses of mercury, even for short periods, can cause changes to brainwaves observed on an electrocortigram.

High mercury levels in the brain, blood or spinal fluid has been found in people with neurodegenerative diseases such as Alzheimer s and Parkinson s disease and Lou Gehrig s disease. Studies have found that people with Alzheimer s disease have blood mercury levels twice as high as those who were free of the disease. This would also explain the 10-times increase in Alzheimer s disease observed in elderly people who get annual flu vaccines for five years. Several studies have shown improvement in MS patients who had their amalgam fillings removed and subsequently went through chelation to purge them of mercury.

What You Can Do

* Try to avoid mercury as much as you are able, including in atmospheric pollution, dental fillings, contaminated seafood and avoid vaccines that contain mercury.

* If you have concerns you can have your urine, hair and stool checked for mercury levels. If the levels are high (above 10 ug/g of creatine) you can use a chelation agent to remove the mercury.

* Perspiration removes mercury. Exercising will increase the perspiration, but a new study found that exercise redistributes the mercury and this concentrates the mercury in the brain and heart muscle.

* Garlic extract neutralizes much of the toxicity and removes a great deal of the mercury from the brain over time. The advantage of this natural substance over drugs is that it can be taken all the time.

* A purified extract of the Chlorella plant have been shown to chelate mercury, and they can be taken daily.

* Vitamin and mineral supplements are useful. In particular, vitamin E protects DNA against mercury damage. Also alpha-lipoic acid, zinc and selenium have proven roles. Zinc and selenium play a major role in protecting the brain against mercury toxicity. It is thought that selenium protects fish from the damage caused by mercury.

* You need cleanse your body of toxic material, including mercury, so that everything is able to work effectively.

Conclusion Mercury is a dangerous toxin that should be avoided as much as possible. Avoidance is not impossible but does require attention to the sources of mercury discussed above. If you believe you may be suffering from mercury toxicity, possibly because you realize that you have had significant exposure and recognize that you have several relevant symptoms, I recommend you consult a naturopathic doctor who will be able to assess your condition and if necessary, order some tests and recommend appropriate treatment.