Risks associated with health-care waste


Box 3.2

Health sec

tor contribution of mercury in the environment

Mercury is used in several medical devices, especially fever thermometers and blood-pressure monitoring equipment.

These represent a hazard in terms of both breakage and long-term disposal. A less well-known source of mercury

in medical waste is batteries, particularly the small button batteries. American and European manufacturers are

removing mercury from their products, but it may still be present in those produced elsewhere (EC, 2006; Department

of Environmental Protection, 2009). Many health-care facilities have adopted a policy of gradual replacement with

mercury-free alternatives.

Health-care facilities also contribute up to 5% of the release of mercury to water bodies through untreated wastewater.

Environment Canada estimates that one third of mercury load in sewerage systems comes from dental practices.

Health-care waste incineration is one of the main sources of mercury release into the atmosphere from health-care

facilities. The United States Environmental Protection Agency estimates that medical incinerators may have historically

contributed up to 10% of mercury air releases.

In the United Kingdom, more than 50% of total mercury emissions come from mercury contained in dental amalgam,

and laboratory and medical devic


The use of mercury in health care is decreasing. Conversely, silver, another toxic heavy metal, is being used in ever

more applications, including as a bactericide and in nanotechnology. In large doses, it can turn a person’s skin

permanently grey. There is increasing concern with both regulators and others about the potential effects of silver,

including the possibility that bacteria develop resistance to the metal and subsequently also develop a resistance to

antibiotics (Chopra, 2007; Senjen & Illuminato, 2009).


Disinfectants, such as chlorine and quaternary ammonium, are used in large quantities in health-care facilities,