Dental Exposure To Mercury – Environmental Impact Of Mercury Containing Dental Amalgams
As part of an ongoing investigation into the risks of medical and dental exposure
to mercury, the House Government Reform Subcommittee on Human Rights and Wellness will hold a
hearing to examine the harmful effects of mercury's discharge from dental offices into municipal sewage
systems. The Subcommittee also hopes to learn more about cost-effective measures to mitigate the impact
of such mercury waste, and to promote improved public health for all Americans.
Congressman Dan Burton, Chairman of the House Government Reform Subcommittee on
Human Rights and Wellness, will hold an oversight hearing entitled, The Environmental Impact on
Mercury-Containing Dental Amalgams.
Mercury is one of the most toxic minerals found in nature, second only to radioactive materials,
stated Chairman Burton. I believe it was sound public health policy to eliminate mercury from
thermometers, blood pressure gauges, cosmetics, light switches, and mining operations. Yet, despite those
safety precaution measures, mercury is still widely used by dentists as a restorative material to fill cavities.
Dentistry exposes patients to mercury in two ways: initially, through its direct implantation of
amalgam into teeth, and then again during the disposal process by increasing the amount of mercury in the
food chain.
Some scientists believe that dental mercury may only be a small percentage of the total National
mercury exposure problem; however, dentists remain a significant source of mercury that ultimately finds
its way into wastewater treatment plants. The Association of Metropolitan Sewerage Agencies
estimates that on average, dentists contribute between 35 percent and 40 percent of the mercury received by
publicly owned sewage treatment plants.
In fact, in many municipalities dentists are the single largest
source of wastewater mercury.
Dental mercury finds its way into wastewater through a variety of means. In a dental office there is
excess amalgam left over after each tooth is filled. In a typical filling procedure, the amalgam is sculpted
to the shape of a patient's natural teeth, thus creating scraps. Also, old fillings are drilled out, and unhealthy
teeth with fillings are extracted.
Depending upon whether the dental clinic in question closely follows bestmanagement
practices, varying amounts of mercury-containing amalgam from these procedures are washed
down the drain.
This process is extremely serious because mercury is highly toxic, and wastewater treatment plants do
not have the means to effectively remove the mercury. The AMSA estimates that it costs as much as $21
million per pound to safely remove mercury once it becomes part of the wastewater stream.
In the absence of that $21 million per pound removal operation, small mercury particles find their
way into rivers and streams, and eventually into drinking water, thereby entering the food chain. Heavy
particles tend to settle into treatment plant sludge. Ultimately, that sludge either gets incinerated, thus
releasing its mercury directly into the atmosphere, or it gets spread out on agricultural fields as a fertilizer.
Over time, bacteria then methylate and the mercury on the fields circulates back into the environment.
Author Notes:
Victor Nessbit contributes and publishes news editorial to http://www.teeth-whitening-smiles.com.
Everything you need to know to get a whiter, brighter smile!
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