Study reveals environmental impact of mercury released from dental amalgam- an unexplored topic
SAN JUAN, Puerto Rico/SPRING, Texas, U.S.: Mercury in dental amalgam contributes to global mercury pollution in multiple ways, such as the illegal diversion of dental mercury into the artisanal and small-scale gold mining industry, crematoria emissions from the deceased and sewage sludge sold to the farmers. This mercury pollution leads to air, water and food contamination that can impact human health negatively. A recent study investigated the different pathways that release mercury from dental amalgam into the environment.
The data from the United Nations Environment Programme has shown that dental amalgam represents more than 20% of the global mercury used in different products. The Minamata Convention (2013) on Mercury - a global treaty to protect human health and the environment from the adverse effects of mercury - is now in force, and 110 countries of the 128 signatories are now working on the implementation for treaty compliance.
The Minamata Convention has listed Dental amalgam as a phase-down product, and the corresponding nine provisions are:
(i) setting national objectives aiming at dental caries prevention and health promotion, thereby minimizing the need for dental restoration;
(ii) setting national objectives aiming at minimizing its use;
(iii) promoting the use of cost-effective and clinically effective mercury-free alternatives for dental restoration;
(iv) promoting research and development of quality mercury-free materials for dental restoration;
(v) encouraging representative professional organizations and dental schools to educate and train dental professionals and students on the use of mercury-free dental restoration alternatives and on promoting best management practices;
(vi) discouraging insurance policies and programs that favor dental amalgam use over mercury-free dental restoration;
(vii) encouraging insurance policies and programs that favor the use of quality alternatives to dental amalgam for dental restoration;
(viii) restricting the use of dental amalgam to its encapsulated form;
(ix) promoting the use of best environmental practices in dental facilities to reduce releases of mercury and mercury compounds to water and land.
The treaty discusses the various ways - sewage sludge, cremation, burial, human waste, and artisanal and small-scale mining etc- by which dental amalgam releases mercury and impacts the environment adversely. However, according to the authors of the study, there has been very little research done on this topic, and this is the first paper to address all of the pathways through which mercury enters the environment from dental amalgam and acts as a cradle-to-grave deadly pollutant.
The authors state that the significant rise observed in mercury pollution from cremation is due to various factors that favour cremation over burial. Two main reasons - cremation being less expensive than burial, and population density gradually reducing the burial space available - are making the rise in cremation a global phenomenon.
The other serious concern is sewage sludge. The European Federation of National Associations of Water Services noted that the major source of the mercury in wastewater in most treatment plants in the EU is from dental amalgam. In order to decrease the mercury content in the sludge from wastewater treatment plants, they advocated a ban on dental amalgam.
Dental amalgam is going to be an important topic of discussion at the upcoming third meeting of the Conference of the Parties to the Minamata Convention on Mercury, to be held in November, 2019. Since the EU has mandated a ban on using dental amalgam for children under 15, pregnant women and breastfeeding women, it is expected that other countries will follow.
The study, titled “Mercury contamination from dental amalgam”, was published in the June 2019 issue of the Journal of Health and Pollution.