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Charlie Brown's Statement at the World Mercury Treaty Negotiations - INC1 President of the World Alliance for Mercury Free Dentistry, delivered an opening statement seeking an international ban on mercury dental fillings before the United Nations Environmental Program (UNEP) in June, 2010 
The World Alliance for Mercury-Free Dentistry Makes Progress at the Mercury Treaty Negotiations The 2nd mercury treaty negotiations, held in Chiba Japan, was a success. Our umbrella coalition, the World Alliance for Mercury-Free Dentistry, "the voice of dental patients worldwide", effectively countered the pro-mercury World Dental Federation (FDI), a lobby group funded by amalgam manufacturers.
Update from Dave Simone on the Intergovernmental Negotiating Committee (INC2) on mercury Dave Simone of The International Academy of Oral Medicine and Toxicology shares his experieinces at the second session of the Intergovernmental Negotiating Committee to prepare a global legally binding instrument on Mercury (INC2) which was held in Chiba, Japan from 24 to 28 January, 2011.
U.S. government calls for the phase-out of dental mercury amalgams! In an extraordinary development that will change the global debate about amalgam, the United States government has announced that it supports a “phase down, with the goal of eventual phase out by all Parties, of mercury amalgam.”
ADA lobbies State Department to dump EPA from UNEP's Intergovernmental Negotiating Committee in favor of pro-mercury FDA. Mercury Policy Project recently wrote a letter  urging the U.S. Government not to succumb to the American Dental Association's recommendations to have FDA assume a leading role in the INC process, given that EPA,  not FDA has the expertise to address the global threat of mercury amalgam releases.
Mike Darcy of MARS Bio-Med Discusses the 2014 EPA Amalgam Separator Regulation Mike Darcy of MARS Bio-Med Discusses the upcoming EPA Amalgam Separator Regulation that will roll out in 2014.
Update from The International Conference on Mercury as a Global Pollutant (ICMGP) The International Conference on Mercury as a Global Pollutant (ICMGP) was held in Halifax, Nova Scotia on July 24-29, 2011. Amanda Just, Freya Koss, and Anita Tibau attended as affiliates of the International Academy of Oral Medicine and Toxicology and recorded some notable information about the mercury used in dentistry as related to the conference:
Bush EPA cuts midnight deal with ADA: Undermining mercury pollution prevention A hold over deal from the Bush administration is allowing tons of dental mercury pollution into the environment that could be prevented. The agreement between the EPA, the American Dental Association and the National Association of Clean Water Agencies stands in stark contrast to pollution reduction initiatives now underway for all other mercury sources.
IAOMT presents science to State Department’s Mercury NGO Stakeholder Meetings August 18, 2011, the State Department held "Mercury NGO Stakeholder Meetings" in Washington, D.C. The meetings were held in preparation for the third session of the Intergovernmental Negotiating Committee to prepare a globally legally-binding instrument on mercury (INC3).
Metro Sewage Authorities Contradict ADA on Waste Mercury Amalgam in Wastewater In 2002, the ADA released an assessment entitled "Evaluation of Mercury in Dental Facility Wastewater." The report argued that dental offices were not a significant source of mercury contamination. The Association of Municipal Sewage Authorities released a critique of the ADA report, taking serious issue with most of its findings.
World Health Organization Report Suggests "Phase Down" of Dental Mercury Amalgam Globally Oct. 11, 2011 The World Health Organization today released its 2009 meeting report on the "Future Use of Materials for Dental Restorations" in preparation for the third of five Intergovernmental Committee deliberations. The WHO report suggests, over time, the global "phase down" of amalgam.
Substance Flow Analysis of Dental Mercury Releases Into The Environment Alex Cain of the EPA published a study in the Journal of Industrial Ecology that evaluated the substance flow analysis of dental mercury releases Into the environment. His comprehensive analysis revealed dentists releaase up to 24 tons of mercury into the environment, a level much more significant than previously thought, which warrants being addressed.
Residual mercury content and leaching of mercury from used amalgam capsules This study investigated residual mercury (Hg) determinations and toxicity characteristic leaching procedure (TCLP) analysis of used amalgam capsules. All capsules tested retained Hg. TCLP analysis of the triturated capsules showed Sybraloye and Contoure leached Hg at greater than the 0.2 mg/l Resource Conservation and Recovery Act (RCRA) limit.
Mercury vapor levels in exhaust air from dental vacuum systems may exceed occupational safety limits Two different methods used to measure mercury (Hg) vapor levels in the air exhausted from dental vacuum systems revealed that Hg vapor release to the atmosphere from dental vacuums can be substantial and exceed human exposure limits.
EPA will mandate dentists install amalgam separators to reduce environmental dental mercury releases The Environmental Protection Agency (EPA) will eventually mandate that dentists nationwide install amalgam separators, which captures 99.5% of waste amalgam containing mercury before it hits the wastewater stream.
Amidst financial crisis, Michigan dentists get $270,000 to install amalgam separators. Dentists have been polluting the environment with dental mercury amalgam waste for over 100 years. All the while oblivious to the fact they were contaminating the environment with mercury or denying they were the most significant source or mercury pollution.
Bio-Cremation a greener way of cremating Matthews Cremation, now offers a combustion-free, potentially greener way of cremating bodily remains called "Bio-Cremation", which emits one tenth the carbon dioxide of traditional cremation according to the company.
Crematory outcry has Minnesota cities weighing risks Crematory outcry has Minnesota cities weighing risks. As cremation rate rises, critics and backers debate potential for such toxic emissions as mercury.  
Crematory Emissions Data Crematory Emissions Data. Outline of Referenced Sources: This is an outline of key points in several documents found to have useful information on the matter of toxins in crematory emissions.
An assessment of mercury amalgam waste in dental wastewater in the U.S. This study performed an assessment of the discharge from dental facilities of mercury in the form of amalgam to surface waters in the United States. Two pathways were examined, effluent from publicly owned treatment works (POTWs) and air emissions from sewage sludge incinerators. Mercury in the form of amalgam from dental facilities to POTWs was estimated to be 6.5 tons
Updates from the Fourth Session of the Intergovernmental Negotiating Committee to Prepare a Global Legally-binding Instrument on Mercury (INC4) The 4th session of the Intergovernmental Negotiating Committee to Prepare a Global Legally Binding Instrument on Mercury (INC4) will meet in mid 2012 to continue to negotiate the text of a treaty to regulate mercury use at a global scale.
Zero Mercury Working Group views on mercury use in dental amalgam The Zero Mercury Working Group believes that the mercury treaty should contain effective "phase down" reduction measures to decrease dental amalgam use, leading to a global amalgam phase-out by a fixed date. Country experiences demonstrate that phasing out amalgam over time is achievable. The Nordic countries have all phased out most amalgam uses.
IAOMT sends experts to the UNEP's INC5 a globally binding treaty on mercury The IAOMT is attending the fifth and final International Negotiating Committee (INC5) meeting by the United Nations Environmental Programme on mercury. IAOMT represents the consensus that amalgam is a risk to the environment, dental workers and the general public, and whose use should be discontinued.
U.N. Calls For Global Phase Down Of Mercury Fillings The International Academy of Oral Medicine and Toxicology, a scientific dental organization, participated in the United Nations Environment Programme's (UNEP) Intergovernmental Negotiating Committee (INC5) meeting, where nations formalized a legally-binding treaty to reduce global use of dental amalgam, a restorative tooth filling material containing 50% mercury.
IAOMT Info-graphic - Dental Mercury’s Toxic Journey Back to the Environment The International Academy of Oral Medicine and Toxicology has released an info-graphic,  Dental Mercury’s Toxic Journey Back to the Environment,  that outlines the many ways in which 340 tons of  dental mercury is released into the global environment yearly.

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Tuesday, 15 November 2011 11:07

Substance Flow Analysis of Dental Mercury Releases Into The Environment

Journal_of_Industrial_Ecology2

In 2007, Alex Cain of the EPA published a study in the Journal of Industrial Ecology that evaluated the Substance Flow Analysis of Dental Mercury Releases Into The Environment. His comprehensive analysis evaluated several release pathways of dental mercury that had not been investigated before. The findings of the study show that the combined total of all dental mercury releases are much more significant than previously thought and warrant being addressed by our government. Of note: while the study examined all sources of mercury released into the environment, this article focuses solely on the dental mercury releases.


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Alex Cain of the EPA
Discusses the findings of his study
which evaluated the substance flow analysis of dental mercury releases into the environment.


Substance Flow Analysis of Dental Mercury Releases Into The Environment

Modeling Mercury Flow

Estimates of mercury disposed of annually were derived in a number of different ways, depending on the product. For dental amalgam, the model estimates three types of mercury.

  • First, mercury that is placed into the teeth of dental patients.
  • Second, it estimates mercury in "contact amalgam" (that comes into contact with teeth, but is left over after the tooth is filled).
  • Third, it estimates mercury in "noncontact amalgam" that is prepared in the dental office but that does not come into contact with patients.

The model separately estimates mercury removed from living patients' teeth, based on estimates of the number of removals that dentists conduct, and adds the result to the "contact amalgam" total.

Distribution factors are applied to contact and noncontact amalgam to determine the amount of mercury that flows to the solid, infectious or hazardous waste management system, to mercury recycling, or to the dental office wastewater system. 

Once in the dental wastewater system, the mercury can be captured by a chairside trap, where again it can flow to the solid, infectious, or hazardous waste management system, to mercury recycling, or back into the dental office wastewater system. Mercury that re-enters the dental office wastewater system can then be captured by a vacuum system filter or an amalgam separator, or be discharged to a sewage treatment plant.

Distribution Factors

Distribution factors indicate the likelihood that a product, or mercury in a product, will follow a given pathway. We used distribution factors to predict the fate of mercury after it is disposed of as municipal solid waste  (MSW), hazardous waste, infectious waste, or wastewater sludge. The distribution factors indicate how much of each category is incinerated versus landfilled, composted, or spread on land. In many cases, we used product- pecific distribution factors to estimate the fraction of the inventory of a product that will be disposed of every year. In addition, we used product-specific factors for the percentage of a product that is recycled rather than discarded as waste, or that ends up in the air and steel recycling system.

For example, dental amalgam distribution factors account for the fraction of amalgam waste caught in a chair-side trap or vacuum filter and for the amount of amalgam in bodies that get cremated or buried. 

Emissions Factors 

Whereas distribution factors indicate the amount of mercury expected to follow a given pathway (e.g., landfilling), emission factors indicate the amount of mercury that each pathway releases to the environment.We developed emission factors for the potential mercury pathways in a product's lifecycle, including releases associated with product use and transport as well as disposal.

For dental amalgam, we considered additional pathways, including human waste, tooth loss, cremation, and infectious waste disposal. Dental amalgam contains approximately 50% mercury, which is slowly released via wastewater systems to the environment through human wastes (Association of Metropolitan Sewerage Agencies 2000).

Some emissions estimates are not based strictly on applying an emissions factor to mercury flow, but rather are independently derived and then plugged into the model. For instance, estimates of mercury releases from dental office vacuum systems are derived not from the amount of mercury used, but from an emissions factor that is based on the number of dentists using amalgam.

Estimates of dental mercury in feces and urine are based on measurements that are not calibrated to the amount of mercury in use. Estimates of mercury in the teeth of corpses are based on mortality statistics and on estimates of the average number of fillings that people have at the end of life.

Results and Discussion

In 2005, switches and relays, dental amalgam, andmeasurement and control devices are responsible for most of the total mercury releases caused by products and most of the releases to land. Switches and relays account for more than half of estimated 2005 product-related air releases, 

Pathways of Product Mercury Releases 

Other significant pathways include disposal of solid waste, a variety of pathways unique to dental amalgam (most notably human cremation), and disposal of sewage sludge.

The model also indicates that the use of dental amalgam may result in significant mercury releases through several little-studied pathways.

The most important of these pathways is cremation of corpses, a source that is growing as cremation becomes more common. The model estimates air releases from this source at more than 2 tonnes in 2005. Dental office vacuum systems are also significant sources of mercury according to the model—more than 1 tonne of air releases  in 2005. In addition, the model calculates that approximately 150 kg of mercury are released annually in exhaled breath as a result of dental amalgam fillings.

...whereas dental amalgam is responsible for more than half of estimated product-related water releases. 

Atmospheric releases associated with dental amalgam use have remained relatively stable, with reduced releases caused by controls on incineration of infectious waste partially offset by increased releases from cremation of corpses.

The model shows that dental amalgam is a major cause of mercury discharges to wastewater. 

Dental office discharges to sewage treatment plants are estimated at 5.5 tonnes, consistent with a recent estimate of 6 tonnes (Vandeven and McGinnis 2005). An additional estimated 1.2 tonnes is discharged to sewage treatment in human wastes as a result of gradual erosion of dental amalgam fillings.

More unexpectedly, the model indicates that dental amalgam is also an important source of mercury releases to the air.

In addition to releases from sludge incineration and land application of wastewater treatment plant biosolids, which are related primarily to amalgam fillings, mercury is  emitted from crematories as a result of amalgam fillings in corpses. Dental offices also release mercury to the air through their vacuum systems, and people exhale mercury as a result of a gradual release of mercury from dental fillings. According to this analysis, dental amalgam is responsible for more than 4.5 tonnes of mercury releases to air, making it a significantly larger contributor of air releases than mercury-containing lamps.

Opportunities and Obstacles in Reducing Product-Related Mercury Releases

The use of mercury in dental amalgam is also expected to continue. Therefore, releases caused by excretion of amalgam by human bodies will continue. Even with continuing use of dental amalgam, though, there is a potential for reducing releases through better waste management and through the use of amalgam separators.

table7-Substance_Flow_Analysis_of_mercury

Table 7 shows the estimated reductions in mercury releases to air, water, and land that would result if dentists were to fully implement best management practices (BMPs) to recycle all scrap amalgam and amalgam captured by existing chair-side traps and vacuum filters.

In addition, if dentists were to universally install amalgam separators capable of removing 95% of amalgam from dental office wastewater, then there would be an even bigger reduction in mercury releases. Projected reductions of air releases from dental amalgam are relatively small because a significant share of estimated air releases caused by dental amalgam results from cremation of corpses, dental office vacuum systems, and exhalation of mercury vapor, none of which would be affected by these measures.

Releases from cremations are forecast to increase due to increased rates of cremation and higher levels of tooth retention due to better dental care.

These estimates of potential mercury reductions from amalgam installation are also based on the assumption that sewage treatment plants capture mercury discharges from dental offices at the same efficiency rate as they capture other mercury discharges. It might be the case, however, that treatment plants are more effective at capturing mercury from dental offices than from other sources, because the mercury from dental offices is more likely to be in particulate form.

If sewage treatment plants are more effective at capturing dental amalgam discharges than we assume, then total mercury discharges to water caused by amalgam would be less than we estimate, and the impact of amalgam separators on water discharges would also be less (Larry Walker Associates 2002).

Cain, A., Disch, S., Twaroski, C., Reindl, J. and Case, C. R. (2007), Substance Flow Analysis of Mercury Intentionally Used in Products in the United States. Journal of Industrial Ecology, 11: 61–75. doi: 10.1162/jiec.2007.1214

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Journal of Industrial Ecology

Journal_of_Industrial_Ecology2 The International Society for Industrial Ecology promotes industrial ecology as a way of finding innovative solutions to complicated environmental problems, and facilitates communication among scientists, engineers, policymakers, managers and advocates who are interested in how environmental concerns and economic activities can be better integrated. The mission of the ISIE is to promote the use of industrial ecology in research, education, policy, community development, and industrial practices.

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