# Mercury in Dental Amalgams: Possible Risks and Regulation

Mercury dental amalgams should not be released into the environment. Photo by Rob’s photostream.

## Mercury Dental Amalgam Risks

Due to the health risks associated with mercury, scientists have performed several investigations to establish whether the use of mercury fillings are dangerous for the patients. According to an EPA report, and various studies, no connection has been established between the use of mercury-based amalgams and health problems.

The use of these amalgams, however, can still pose a threat to the environment, if they are not dealt with and disposed of properly.

Generally, the release of amalgam wastes into the environment must be avoided; mercury-containing wastes, coming for instance from dental surgery, should be separated from the other waste, using appropriate separator devices. Subsequently, they should be collected as a special medical waste.

## Scales to Measure Concentration: Parts per Million (ppm)

The concentration of a certain substance in solution can be described using different scales. For diluted solutions, we often use the term, parts per million (ppm).

This scale indicates a unit of weight, for instance grams, divided by a million of the same unit – in this case a million grams.

For example, a solution with Hg concentration of 2 ppm means that 2 grams of mercury are present in 1 million (1,000,000) grams of the solution. As 1 million grams is equivalent to 1000 kg (= 1 tonne), 2 ppm concentration is equivalent to 2 g in 1000 kg (or 2 g per tonne), or 2 mg in 1 kg.

## Scales to Measure Concentration: Milligrams per Liter (mg/l)

Another way to express the concentration is considering how many milligrams of a certain substance are dissolved in a liter of solution (mg/l).

The concentration expressed in this scale can be converted to ppm and vice versa. To convert ppm into mg/l, usually an assumption is made: the density of the solution is considered equal to 1 g/ml, as if it were pure distilled water. For diluted solutions, this is an acceptable assumption to make, as their effective density does not differ substantially from that of distilled water.

Based on that, a weight of 1000 g is equivalent to 1000 ml (1 liter) of solution.

Therefore, considering the example above, a concentration of 2 ppm corresponds to 2 mg in 1 liter (2 mg/l).

Calculations to convert mg/l into ppm. Photo by Shaunette Babb.

## Calculating the Concentration of Mercury in Water

To answer the question, if 135 mg are present in 3.4 liters, this gives a concentration of 39.71 mg/l. This value corresponds to 39.71 ppm, which is well above the EPA limit of 0.2 ppm.

This solution should be, therefore, properly treated and disposed, as mentioned above.

If the mercury is present in the form of small particles, the number of particles in solution will vary, depending on the sizes of the particles.

For instance, if we assume that all particles have a spherical shape, with a diameter of 10 mm, then each particle will have a volume of 5.2×10-7 cm3. As the density of Hg is 13.53 g/cm3, a weight of 135 mg of mercury corresponds to a volume of about 0.01 cm3. Therefore, the number of particles will be:

0.01/(5.2×10-7) = 1.9×10+4

This means approximately 20000 particles.

Similar calculations can be performed considering particles of different dimensions and/or shapes.

## Sources

Environmental Protection Agency. Mercury, Laws and Regulations. Accessed May 15, 2012.

Watson, G., et al. Prenatal exposure to dental amalgam: Evidence from the Seychelles Child Development Study main cohort. (2011). Journal of the American Dental Association. Accessed May 15, 2012.

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• http://www.iaomt.org Freya Koss

Dear Clara,

MERCURY IS MERCURY IS MERCURY!! IT IS A POISON!
re: Mercury in Dental Amalgams, Possible Risks and Regulations

As a scientist, you note that you are aware that mercury is an extremely toxic element. In fact, you mention that in some applications Hg has been replaced by less toxic elements. You are correct, however, you don’t mention that one of those applications is silver amalgam dental fillings containing 50% mercury, a known neurotoxin. Half of U.S. dentists no longer use silver mercury amalgam fillings because of its extreme toxic nature to health and the environment. A large percentage of UK dentists also have chosen not to use fillings containing mercury….they are using white non-mercury composite fillings.

I refer you to the website of the International Academy of Oral Medicine and Toxicology, a scientif dental organization that has been researching the dangers of mercury fillings for more than 30 years. Search for the scientific references contained in their “Petition for Reconsideration” filed by the IAOMT with the U.S. Food and Drug Administration. There are references to the levels of mercury exposure from these fillings and the various diseaases associated wiht mercury fillings, such as MS, Lupus Parkinson’s, ALS and Alzheimer’s Disease.

There are also references related to the dangers of prenatal exposure from maternal dental fillings.

Not only is the patient at risk, but dental personnel as well. Note: mercury exposure in female dental personnnel has shown a very high rate of infertility, miscarraige and cancer. Also, the Hg in the maternal amalgam fillings of pregnantn women is transferred to the developing fetus, and thus can damage the developing nervous system. This type of exposure has been linked as a contributing factor to autism .

I am an injured consumer. r one was struck with double vision 14 years ago and diagnosed with Multiple Sclerosis, Lupus and Myasthenia Gravis Mercury is known to effect the immune system, and therefore can cause autoimmune diseases.

As a scientist, I highly encourage diligent reliable research on your part rather than referencing articles from the Journal of the American Dental Assoc. a trade organization with financial stakes in keeping amalgam fillings alive. In fact, the ADA would prefer that dental amalgam take a slow quiet death. The ADA does not want to be held accountable for the millions of people who have suffered and died of amalgam mercury poisoning. They preach “preventive dentistry” rather than the mandatory removal of mercury filling from use.

Unfortunately for the public, the ADA has suppressed the risks of mercury fillings for more than 100 years. From a logical and scientific point of view, mercury fillings should be banned fro use immediately as was done in Sweden, Denmark and Norway.

There is no sane reason for promoting or endorsing its use for any segment of the population.

I hope that you will reconsider your comment and write a follow up article with appropriate recommendatons to the public.

Thank you,
Freya Koss
Director, Pennsylvania Coalition for Mercury-Free Dentistry
U.S.A.

• Paul

They are not interested Freya what you say is exactly right the people who are behind amalgam fillings want a slow retraction of these fillings so they can continue to financially benefit from their placement. This is an example of capitalism at its worst maybe the communists were right capitalism can have very evil undertones. But the corporations need to understand it is the people who hold the true power and if everyone boycotts these fillings as they should after all who wants something that toxic that has never been prooven scientifically to be safe, but has been shown to leak mercury vapours in their mouth !!!! The indifference these pricks show to an individuals right to live a healthy life makes me hostile, not angry not annoyed not irritated hostile!!!!!! an in the words of Rage Against The Machine an a song that is totally appropriate to this situation I say We Gotta Take The Power Back!!!!!

• Michael Dungelman

I am truly curious as to when the people in charge of protecting the people they represent will stop accepting pro-amalgam contributions to campaigns and stand up for what is right. I am 31, and only five weeks ago it was brought to my attention that the ten mercury amalgams in my mouth have been gradually poisoning my body since the moment they were set. I may need to take out a loan to properly remove the amalgams, but my life is most certainly worth it! Someday my mouth won’t taste like metal, and I hope it is very soon. Since my current dentist believes that mercury amalgams are ‘safe until proven harmful’ I will need to find a dentist in New Hampshire or within a two hour drive that I can trust to remove this poison.