Why this document still shows up in dental mercury discussions
In 2005, the World Health Organization (WHO) issued a short policy paper titled Mercury in Health Care (WHO/SDE/WSH/05.08). WHO’s own words explain why mercury in health care—including dental amalgamthreatens patients, workers, and the environment, and they lay out a short-, medium-, and long-term strategy to cut mercury use and exposure. IAOMT cites this paper as Reference #1 for SMART because it puts dental amalgam’s mercury content and vapour risk in plain policy language.
That is why the paper anchors public education about dental amalgam: WHO itself documents that amalgam is roughly half mercury and that mercury vapour is a serious exposure route.
What WHO says about mercury toxicity
WHO opens with elemental mercury’s behavior: it is a liquid metal that readily vaporizes, can remain in the atmosphere for up to a year, deposits globally, and in aquatic systems can convert to methylmercury that accumulates in fish.
On health effects, the paper states that mercury is highly toxic, especially as methylmercury; that inhaled vapour may be fatal; and that mercury can be harmful if absorbed through the skin. It reports that about 80% of inhaled mercury vapour is absorbed into the blood through the lungs, with possible effects on the nervous, digestive, respiratory, and immune systems and the kidneys, plus lung damage. Listed outcomes include tremors, impaired vision and hearing, paralysis, insomnia, emotional instability, fetal developmental deficits, and attention and developmental delays in childhood. WHO also notes that studies available by 2005 suggest mercury may have no threshold below which some adverse effects do not occur—meaning “a little bit” is not automatically harmless.
Health-care releases—and where dental amalgam fits
WHO identifies health-care facilities as important mercury sources, especially via medical-waste incineration and untreated wastewater. Among figures cited in the paper:
- A U.S. EPA 1997 estimate that medical waste incinerators may have accounted for as much as 10% of U.S. mercury air releases.
- An estimate that health-care facilities may have accounted for as much as 5% of mercury releases in wastewater.
- An Environment Canada estimate that more than one-third of mercury load in sewage systems is due to dental practice.
On dental amalgam, WHO states it “is the most commonly used dental filling material,” typically about 45–55% mercury, roughly 30% silver, and other metals such as copper, tin, and zinc. The paper further states that in 1991 WHO confirmed mercury in dental amalgam as the greatest source of mercury vapour in non-industrialized settings, with exposure for the affected population “significantly exceeding those set for food and for air.” (The 2005 paper attributes that confirmation to WHO IPCS CICAD material.)
WHO also summarizes United Kingdom data reported to OSPAR: annually, 7.41 tonnes of amalgam mercury discharged to sewer, atmosphere, or land, plus 11.5 tonnes recycled or disposed with clinical waste—and that amalgam plus laboratory and medical devices together accounted for about 53% of total mercury emissions in that reported context. Incineration and crematoria are listed as major sources as well.
Bottom line from WHOs own figures: amalgam is a major mercury source in health care and the environment—not an inert “silver” filling.
Occupational exposure indoors
WHO identifies inhalation of liquid mercury vapours as the most common potential occupational route and the greatest health risk for metallic mercury. Even small spillssuch as from broken thermometerscan push indoor air above recommended limits if cleanup is poor. Because vapour is odourless and colourless, people can inhale it unknowingly. Mercury beads can hide in cracks or cling to porous materials; footwear can track contamination; inadequate disposal may expose patients and staff.
Those points hit dentistry directly: when amalgam mercury is disturbed, vapour and contamination pathways are a real protection issue for patients and staff—the same problem SMART protective measures are built to control.
WHO’s strategy: protect now, substitute over time
WHO recommends national assessments of mercury use and waste programs, then phased collaboration:
Short-term. Develop cleanup, waste-handling, and storage procedures. Until mercury-free alternatives are accessible, WHO says safe handling that minimizes patient, occupational, and community exposures is “imperative, including staff training, education, protective gear, spill response, engineered storage, and proper waste containment. Countries with affordable alternatives should plan reductions and replacements (with a temporary sphygmomanometer calibration caveat noted in the paper).
Medium-term. Inventory mercury devices; replace what can be replaced; take back old equipment; discourage import and sale of mercury health-care devices; keep recovered devices from re-entering supply chains.
Long-term. Support bans and mercury-free alternatives; help countries write national guidance and laws for mercury health-care waste; align with Basel Convention principles; allocate resources for procurement and sound waste management.
WHOs own short-term language prioritizes exposure control while mercury remains in use—not waiting for perfect substitution everywhere before protecting people.
How WHO’s findings power SMART mercury education
| Topic | What WHO 2005 states | How IAOMT SMART materials commonly use it |
|---|---|---|
| Amalgam mercury content | About 45–55% mercury | Reference #1 for “approximately 50% mercury” |
| Vapour / exposure | 1991 WHO confirmation of amalgam as greatest vapour source in non-industrialized settings; environmental and occupational pathways | Broader SMART literature cites many additional studies on vapour, particulate, and procedural releases—not all in this policy paper |
| Protective measures | Training, protective gear, spill response, storage, waste containment | Specific operatory measures (dam, high-volume evacuation, filtration, respirators, barriers, separators, etc.) from a larger reference set |
| Name “SMART | Not mentioned | IAOMT-named recommendations (name formalized 2016; updates noted 2019 per IAOMT) |
| Decision to remove amalgam | Not a removal guideline | SMART addresses protection when removal is performed; IAOMT also advises against amalgam disruption for pregnant/breastfeeding patients or staff |
WHO 2005 is hard hazard framing from the world’s leading public-health authority. SMART’s protective measures put that same minimize-exposure mandate into the dental operatory.
Practical takeaways
- Amalgam is mercury-containing. WHO places typical content near half the filling by weight (45–55%).
- Vapour matters. About 80% of inhaled vapour is absorbed; it cannot be smelled.
- Clinical and environmental. Amalgam waste, incineration, wastewater, and cremation appear alongside medical devices in WHOs emissions discussion.
- Protective handling is WHO short-term policy. Training, gear, spill response, and waste containment are part of WHO’s own recommendations.
- Substitution is the longer arc. Medium- and long-term steps aim to reduce and eliminate mercury devices.
- Ask which document. If a clinic cites “WHO,” ask which paper, which statement, and whether it is describing WHO text or a clinic-specific safety protocol.
Bottom line
WHO’s Mercury in Health Care policy paper (WHO/SDE/WSH/05.08, 2005) is a concise public-health brief: mercury from health care—including dental amalgam—contributes to human exposure and environmental release; inhalation of vapour is a central occupational hazard; and countries should combine immediate safe-handling protections with a path toward mercury-free alternatives. It is a foundational citation for amalgam mercury content and sector-wide risk framing. It is not a WHO-branded amalgam removal technique. The accurate connection for readers evaluating SMART-style measures is that WHO argued health-care mercury exposures should be minimized with training, protective gear, and sound waste practice—principles specialized dental hygiene protocols later elaborate in clinical detail.
Citations
- World Health Organization. Mercury in Health Care: Policy Paper. Geneva: WHO Department of Protection of the Human Environment, Water, Sanitation and Health; 2005. WHO/SDE/WSH/05.08.
– Current PDF (verified 2026-09-12): https://www.who.int/docs/default-source/wash-documents/mercury-in-health-care.pdf
– WHO publications record: https://www.who.int/publications/i/item/WHO-SDE-WSH-05.08
– Legacy URL cited by IAOMT (http://www.who.int/water_sanitation_health/medicalwaste/mercurypolpaper.pdf) returned HTTP 404 as of 2026-09-12.
- World Health Organization. Publication landing page for WHO/SDE/WSH/05.08 (catalog date displayed as 1 January 2005). https://www.who.int/publications/i/item/WHO-SDE-WSH-05.08
- Health Care Without Harm. “World Health Organization Mercury in Health Care Policy Paper (resource dated August 1, 2005). https://global.noharm.org/resources/world-health-organization-mercury-health-care-policy-paper
- International Academy of Oral Medicine and Toxicology (IAOMT). The Safe Mercury Amalgam Removal Technique (SMART) reference list (WHO 2005 as Reference #1). IAOMT SMART materials cite WHO 2005 as Reference #1.
Note: The 2005 policy paper cites WHO IPCS CICAD material for the 1991 “greatest source of mercury vapour… statement. This draft reports that claim as stated by the 2005 paper, without a separate full audit of CICAD 50.
