Mercury Containing Medical Measuring Devices

Overview

Why does it matter?

About the project

Mercury is highly toxic to humans and ecosystems and is considered by WHO as one of the top ten chemicals or groups of chemicals of major public health concern. Mercury pollution exposes people and wildlife, regardless of proximity to source, to harmful effects. Exposure to mercury can result in adverse impacts on the nervous, digestive and immune systems, lungs and kidneys.

Mercury Containing Medical Measuring Devices (MCMMD) have formed an essential component of medicine for centuries. The first mercury-added thermometer was developed by Fahrenheit in Germany in the early 18^th century; at the end of the 19^th century came the sphygmomanometers. Owing largely to environmental and human health concerns, high-income countries began to phase-out the manufacture and use of these devices beginning in the early 2000s.

The Minamata Convention on Mercury covers a range of issues associated with mercury production, use, emissions and releases, as well as waste management, providing a list of uses in which the manufacture, import and export are restricted, and applicable phase-out dates or reduction targets. The Part I of Annex A of the Convention text specifies that parties to the Convention must ban the following non-electronic measuring devices except non-electronic measuring devices installed in large-scale equipment or those used for high precision measurement, where no suitable mercury-free alternative is available: a) barometers b) hygrometers c) manometers d) thermometers e) sphygmomanometers.

Hg in medical measuring devices Learn more why it matters and explore the catalogue of resources, news and events.

Resources

News

Events

Related links

WEBINAR - Managing mercury waste from dental amalgam and medical measuring devices: sharing existing knowledge and initiatives

Releases in healthcare settings are primarily associated with damaged equipment and poor waste management practices. Mercury-added thermometers are comprised of a vacuum sealed glass tube enclosing a small bead of mercury expands or contracts in response to temperature. They are typically discarded when the glass chamber is ruptured, and a spill occurs. As mercury evaporates at room temperature; a small quantity spilled in a confined space can result in high air contamination levels.

Mercury-added sphygmomanometers contain substantially more mercury than thermometers, though are much less prone to rupture. The devices themselves are comprised of a U-shaped glass tube containing a column of mercury. The column rises or falls in response to air pressure introduced by the blood pressure cuff. Because this air-mercury interface is imperfect, most sphygmomanometers experience some level of mercury release over their lifetime though in concentrations highly unlikely to produce adverse health outcomes.

Despite the success of the Minamata Convention on Mercury, several challenges remain. Mercury-added devices have been wedded to medicine for centuries, resulting in firmly rooted perspectives and processes across the supply chain. Procurement officers in hospitals are hesitant about mercury-free devices due to higher upfront costs and concerns over user acceptance, and some physicians and medicals practitioners were sceptic to adopting mercury-free alternatives, arguing less accuracy from the alternatives. Over time, increased validation and improved digital technology settled the debate, leading to broad acceptance in high-income countries. However, this discussion is only just starting in many low- and middle-income countries, spurred by the Minamata Convention.

Mercury-added medical devices are still widely used in healthcare facilities and research shows that these devices are often improperly disposed of with non-hazardous waste, highlighting a lack of awareness and knowledge on proper waste management at the facility level.