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OVERVIEW (as listed on page):

Health Care in the Minamata Convention:

  • Vaccines
  • Thermometers

Health Aspects of the Minamata Convention:

  • Article 16: Health aspects
  • Article 7: Artisanal and small scale
  • Article 4: Mercury-added products
  • Article 10: Storage of mercury
  • Article 12: Contaminated sites
  • Article 17: Information exchange
  • Article 18: Public information, awareness, and education
  • Article 19: Research, development, and monitoring

Health Care in the Minamata Convention

The WHO has been proactively addressing different aspects of mercury use in health care. Major attention has been devoted to replacement of mercury thermometers and sphygmomanometers in health care facilities on the basis that validated and affordable non-mercury alternatives are available. In order to assist decisions relating to materials for dental restoration, WHO convened a technical meeting and published a report detailing the features of dental amalgam and other materials. Significant efforts will be required to implement mercury replacement and storage of mercury-added products currently used in health care (1,2).

The WHO and UNEP documents listed under references regarding toxicology of different forms and compounds of mercury and methodologies for mercury health impact and other related documents will be instrumental on several aspects of the Minamata Convention. WHO regional offices will be active in the communication and adjustment of this wealth of knowledge for each specific context. Useful documents to trigger action can be obtained at references 5 and 6; translation of these documents will facilitate their use. Institutional arrangements for the convention will involve a conference of Parties, a Secretariat, and subsidiary technical bodies that may be established.

In brief, further implementation of the mercury convention implies mobilization of different resources – in kind, technical and financial for training and implementation of actions. The health sector will surely need to play a relevant role in several of these activities. We recommend that professionals from health and other sectors be trained as mentors to act upon these mercury-related activities.


While the Minamata Treaty proposes to outlaw the production, export, and/or import of mercury-added products (listed in part I of Annex C) after the phase out date specified to each of the products, thiomersal (which contains ethyl mercury) was exempted from this stipulation (7). Thiomersal is an organomercurial (ethyl mercury) compound commonly utilized as a preservative in many vaccines and other drug products. This compound is well recognized for its antiseptic and antifungal properties, thus offering great protection from contamination of potentially life-threatening microbes. Unlike methyl mercury, ethyl mercury has a half-life of 5 to 7 days in the blood stream before it is excreted by the body through urine. Additionally, ethyl mercury has not been found to bioaccumulate in aquatic food chains, and, more importantly, due to its short half-life in human blood, it also has not been found to cross the blood- brain barrier.

Thiomersal use in vaccines has long been a contentious issue. Thiomersal containing vaccines are globally used to protect more than 80 million infants. In recent years, the use of thiomersal has been strongly critiqued as a growing false sentiment of the potential of this compound to induce adverse neurotoxicological effects has heightened. This paranoia was further instigated with the publication of an article by Andrew J. Wakefield linking autism to vaccines. This article was published in a prominent British medical journal, The Lancet, in 1998. After nearly a decade of thorough investigation, in 2010, Wakefield’s research article – which was one of the most influential pieces on this topic – was retracted as there was an apparent bias present in the paper. As many news outlets reported, apparent financial and scientific conflicts that the author did not disclose in his paper were present; there were also questions regarding ethical procedures of the study. Moreover, that same year the author of this paper – considered fraudulent by the Lancet – was barred from medical practice in the UK. Not only did this piece greatly damage the reputation of thiomersal vaccines, but as reported by various news media outlets, vaccination rates in Britain dropped and measles cases soared (particularly in 2012).

Since the publication of this paper in 1998, numerous national and international organizations (such as the American Committee on Immunization Practices (ACIP), United Nations Environmental Programme (UNEP), Center for Disease Control (CDC), US Food and Drug Administration (FDA), Institute of Medicine (IOM), American Academy of Pediatrics (AAP), US Public Health Service, American Academy of Family Physicians (AAFP), and World Health Organization (WHO)) have refuted the notion that thiomersal can be implicated with developmental delays or a decrease in neuropsychological performance. Various studies (including some that are published by the CDC and the EPA) have also renounced any causal relationship between prenatal, neonatal, and infant exposure to vaccines that contain thiomersal and an increased risk for autism spectrum disorder (ASD). For a more comprehensive list of these studies, see reference number 8 (listed below).

Thiomersal-free vaccines would compromise current global immunization efforts due to increased logistics and financial costs, likely unaffordable where vaccines are mostly needed. Also, a new licensing application for new products would require extensive validation studies, with no guarantee that better vaccine preservatives could be produced. In fact, many health organizations encourage the addition of thiomersal in vaccines; not only does this protect the recipient from contracting deadly infections, but it also allows for a longer storage life of the vaccine. Eliminating thiomersal from vaccines can pose safety issues in terms of potential bacterial contamination as well as a high refrigeration costs for storage.

Thermometers and Sphygmomanometers

Mercury thermometers, like other mercury-added products (listed in part I of Annex C) are to be phased out by the year 2020, according to the Minamata Treaty guidelines. While mercury-in-glass thermometers are quite prevalent, they can pose health hazards on several levels. These thermometers may contain anywhere from 0.5 – 3 grams of metallic mercury. Unlike other forms of mercury, metallic mercury poses its biggest threat in that it vaporizes and, therefore, can be inhaled – ingestion and dermal contact are not of great concern (as the body does not absorb significant amounts through these exposure routes). On numerous occasions, many thermometers have been broken – in fact, at the prestigious "Fredrico Gomez" Children's Hospital in Mexico City, there is a documented breakage rate of about 385 thermometers per month. This amounts to well over 4,000 per year (3). While broken thermometers may be cleaned up in a timely manner, it is common that the mercury from these thermometers balls up and escapes into small cracks or behind objects. It can also cling to objects (shoes, brooms, etc.) and very swiftly spread from one place to another. Hidden mercury vaporizes and is inhaled by those around, thus entering the bloodstream. Once in the body, metallic mercury can remain there for weeks or months; if it makes it to the brain, it can be converted to an inorganic form and stay “trapped” in the brain for a lengthy period of time (causing damage). Within the environment, Mercury vapor can also travel long distances before settling into the atmosphere where it bioaccumulates, further volatizes, or is converted to methyl mercury by microorganisms.  Mercury clean-up can be an extremely tedious and costly process (4).

Children and adults may experience negative health effects caused by both short and long-term exposures to mercury vapors. Common short term health impacts include cough, shortness of breath, chest pain, nausea, vomiting and/ or diarrhea, eye irritation and/or vision difficulty, and headache. Long term exposure tends to cause health detriments that may be a bit more serious in nature and are oftentimes more difficult to reverse and/or treat. These health impacts include anxiety, anorexia and/or loss of appetite, sleeping impediments, irritability, fatigue, memory loss, tremors, hearing/vision loss, and in severe cases, brain and/or kidney damage. In addition to these manifestations of mercury exposure, inhalation of mercury vapors can be particularly detrimental to children, pregnant women, and nursing mothers. Unlike adults, children may not report or clean up a broken mercury thermometer as quickly or diligently; in contrast, children may play with the mercury thus increasing exposure. Additionally, children have faster respiration rates (as their lungs are smaller than adults’), and mercury vapors tend to be a bit denser than air thus concentrating closer to the ground. These details result in greater intake of mercury vapors in children. Not only can mercury vapor inhalation result in the aforementioned health effects, but mercury absorption in the body has been linked to neurodevelopmental anomalies in children and fetuses (mercury can pass from a mother’s body to her unborn child and to any children she may be breastfeeding).

Various mercury-free thermometers have proven to be as accurate in temperature measurement as mercury-in-glass thermometers. While, initially, mercury-free thermometers may be a bit more expensive, hospitals in several countries – including Argentina, Mexico, and the Philippines – that have substituted mercury-in-glass thermometers with digital apparatuses report cost savings (factoring mercury clean-up costs and the costs of disposal of mercury-containing units). The digital devices prove to be more versatile and durable, and the breakage rate is much lower than that of mercury thermometers. Not only are the digital thermometers safer for children to use, there are quite a few features that are not available on the mercury thermometers. These features include: a larger, digital display (may result in a more accurate reading of the temperature), rapid response time (~10 sec. or less), memory function (that stores last recorded temperature), automatic shut-off, long battery life (mercury-free battery), solar powered option, dual scale (C and F), and a usual minimum of one year warranty.


Health Aspects of the Minamata Convention

The Minamata Convention’s primary objective is to propagate regulatory measures that will protect human health and the environment from anthropogenic mercury and mercurial compound emissions and releases. Human health is, both, directly and indirectly addressed and emphasized throughout the convention. The proceeding will highlight and reiterate the specific articles in which the health sector will have a key role in the protection of human and environmental health as depicted in the Minamata Convention.

Article 16: Health aspects

The convention encourages parties to promote the development and implementation of strategies and programs to identify and to protect populations at risk (particularly vulnerable populations). These approaches may include adopting science-based health guidelines, setting targets for exposure reductions, and/ or public education techniques that involve stakeholders.

Healthcare services for prevention and treatment of exposed populations are required, especially in artisanal small scale gold mining sites. For such, training healthcare personnel is encouraged. The WHO Training Package for the Health Sector for Children’s Health and the Environment includes a package for Adverse Health Effects of Heavy Metals in Children. For more information, please see Reference number 9 (listed below).

In considering health-related issues and activities, it is essential that consultation and collaboration – as well as information exchange – with WHO, International Labor Organization (ILO), and other relevant organizations take place (7).

Article 7: Artisanal and small-scale gold mining

Artisanal and small-scale gold mining sites as well as entities that conduct any processing by which mercury amalgamation is utilized to extract gold from ore shall take steps to reduce and/or eliminate the use of mercury as well as mercury emissions and release to the environment. Each participating Party is to inform the Convention Secretariat if any of the preceding entities have more than an insignificant presence in its territory; this may result in the development and implementation of a National Action Plan (NAP)* in accordance with Annex C of the Convention. Parties may collaborate with one another in the development of mercury diversion strategies, educational/outreach initiatives, research  into non-mercury alternatives, technical and financial assistance, as well as general information exchange to ensure the best means by which to fulfil the measures in the Article (7).

*National Action Plans (NAPs) are essential in the preparation of the implementation of the Minamata Convention.

In accordance with paragraph 3 of Article 7 of the Convention and Annex C as well as specified by the Global Environmental Facility (GEF), NAPs are to include:

1.   National objectives and reduction targets;

2.   Actions to eliminate:

   a.   Whole ore amalgamation;

   b.   Open burning of amalgam or processed amalgam;

   c.   Burning of amalgam in residential areas, and;

   d.   Cyanide leaching in sediment, ore or tailings to which mercury has been added without first removing the mercury;

3.   Steps to facilitate the formalization or regulation of the artisanal and small-scale gold mining sector;

4.   Baseline estimates of the quantities of mercury used and practices employed in artisanal and small-scale gold mining and processing within its territory

5.   Strategies for promoting the reduction of emissions and releases of, and exposure to, mercury in artisanal and small-scale gold mining and processing, including mercury-free methods;

6.   Strategies for managing trade and preventing the diversion of mercury and mercury compounds from both foreign and domestic sources to use in artisanal and small-scale gold mining and processing;

7.   Strategies for involving stakeholders in the implementation and continued development of the NAP

8.   A public health strategy on the exposure of artisanal and small-scale gold miners and their communities to mercury. Such a strategy should include, inter alia, the gathering of health data, training for health-care workers and awareness raising through health facilities;

9.   Strategies for providing information to artisanal and small-scale gold miners and affected communities, and;

10.  A schedule for the implementation of the NAP (10).

For more on the NAP guidelines, take a look at the Global Environment Facility's Initial Guidelines for Enabling Activities for the Minamata Convention on Mercury (Reference number 10). 

See the National Action Plan for the Phase out of Mercury in Artisanal and Small-Scale Gold Mining in the Philippines.

Article 4: Mercury-added products

By the specified phase-out dates, participating parties are to take appropriate measures to cease the manufacture, import, or export of mercury-added products (listed in Part 1 of Annex A of the Convention) – exemptions may be made in extreme circumstances and under well-monitored conditions. Five years after the date of entry into force of the Convention, the progress and effectiveness of measures taken shall be reviewed; any further information on alternatives to mercury-added products shall be made public. The manufacture and distribution of mercury-added products not included in the Convention should be discouraged by each Party (7).

Article 10: Storage of mercury

It is recommended that each Party take measures to ensure that the interim mercury storage is undertaken in an environmentally sound manner, taking into consideration the relevant guidelines developed under the Basel Convention (for the purpose of controlling trans boundary movements of hazardous wastes and their disposal) (7).

Article 12: Contaminated sites

It is imperative that participating parties develop appropriate strategies for the identification and assessment of mercury-contaminated sites. These procedures are to include human health as well as environmental risk assessments and are to be carried out in an environmentally sound manner. Public engagement, cost-benefit analyses, and outcome validation may also be included in the assessment of contaminated sites (7).

Article 17: Information exchange

Each of the participating parties should designate a national focal point for the exchange of information and partake in scientific, technical, economic, and legal information exchange concerning mercury and mercurial compounds. No information on health and safety of humans or the environment is to be regarded as confidential. This information exchange may occur directly through the Secretariat, and the Secretariat will facilitate cooperation in the exchange of information (7).

Article 18: Public information, awareness, and education

Each party is to promote and facilitate information to the public regarding the health and environmental effects of, as well as alternatives to, mercury and mercury compounds. Research, development, and monitoring activity results, along with education, training, and public awareness, are also to be shared with the public (especially vulnerable populations) and intergovernmental and non-government organizations (7).

Article 19: Research, development, and monitoring

Participating parties are encouraged to collaborate in the development of mercury use, consumption, and emission inventories. Mercury impact assessments (including information on the environmental cycle and the environmental fate of mercury) and geographically representative monitoring of mercury levels are to be conducted utilizing harmonized methodologies for these activities. Parties should build on existing monitoring networks and research programs (7).


1. WHO - Departamento de Salud Publica y Medio Ambiente Agua, Saneamiento y Salud - El Mercurio en el Sector de la Salud.
2. WHO – Health Care without harm –Mercury-free health care.
3. Selendy, Janine MH. Water and Sanitation-related Diseases and the Environment: Challenges, Intervetions, and Preventative Measures. Hoboken, NJ: Wiley-Blackwell, 2011. p353.
4. WHO, 2011: Replacement of mercury thermometers and sphygmomanometers in health care
5. United Nations Environment Program – Chemicals Branch and WHO Department of Food Safety, Zoonoses and Foodborne Diseases (2008). Guidance for identifying populations at risk from mercury exposures.
6. Poulin J, Gibb H. (2008) Mercury: Assessing the environmental burden of disease at national and local levels. Editor, Prüss-Üstün A. WHO, Geneva, 2008. (WHO Environmental Burden of Disease Series No. 16)
7. The Minamata Convention on Mercury (Text)
8. American Academy of Pediatrics - Vaccine Safety: Examine the Evidence
9. Adverse Health Effects of Heavy Metals in Children
10. Global Environment Facility's Initial Guidelines for Enabling Activites for the Minamata Convention on Mercury

Additional Resources

See what the following institutions have to say about thimerosal use in vaccines:


Last Updated on Wednesday, 16 April 2014 15:00

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