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GENEVA, Switzerland: The United Nations Environment Programme (UNEP) has released the most comprehensive assessment of global emissions of mercury to date. It found that communities in developing countries especially are facing increasing health and environmental risks linked to mercury, which is emitted by various industries, including the dental industry.
Mercury is a naturally occurring element in the environment and derives from many natural sources. However, anthropogenic sources of mercury emissions account for about 30 per cent of the total amount of mercury entering the atmosphere each year. According to the recently published report, an estimated 1,960 tonnes of mercury were emitted into the atmosphere in 2010 worldwide as a direct result of human activity. It also revealed that about 50 per cent of anthropogenic mercury emissions come from Asia, with about 75 per cent coming from China alone, which is about one-third of the global total.
Artisanal and small-scale gold mining and coal burning for electricity generation were found to be the largest man-made sources, accounting for about 62 per cent of the annual total emissions to air. This poses an increasing threat to the health of some ten to 15 million people in Africa, Asia and Latin America in particular, the investigators said.
Another use of mercury is in amalgam for dental fillings. It can be emitted and released during the production and preparation of fillings and through the disposal or removal of fillings. In addition, mercury from removed fillings can be recycled or pass into solid waste and wastewater. However, mercury emissions due to the preparation of fillings and disposal of removed fillings are not currently quantified. Values associated with the dental industry are available for mercury emitted through the cremation of bodies only, which accounted for approximately 3.6 tonnes in 2010.
In December 2012, UNEP and other organisations such as the WHO and the FDI World Dental Federation held a meeting in London with the aim of establishing a research agenda on dental materials based on the 2009 WHO recommendations to achieve a phase-down of dental amalgam. At the meeting, UNEP officials estimated that dental amalgam accounts for 2 per cent of anthropogenic mercury emissions to air and 8 per cent of mercury demand or consumption in processes and products.
In the current report, the investigators said that some 340 tonnes of mercury are used annually in dentistry, of which up to 100 tonnes (20 to 30 per cent) are likely to enter the waste stream.
Despite many efforts to tackle the problem, global action to reduce the risks posed by exposure to mercury has been comparatively slow, according to UNEP. The organisation thus recommended that governments promote the transition to safe alternatives by introducing regulations in order to reduce the release of mercury, which can circulate in the environment for centuries.
There is currently no data available on the environmental impact of the alternatives to dental amalgam, such as resin composites and glass ionomers, the investigators added.
The full report, titled “Global mercury assessment 2013”, can be downloaded from the organisation’s website. It will be presented at the meeting of the International Negotiating Committee on Mercury currently being held in Geneva.
