What are the main challenges caused by mercury? 

Mercury has been used in several industrial applications during the past few centuries. During the Spanish colonisation of South America, it was used in mining to extract gold and silver. The element was also used in thermometers, barometers, mercury switches and relays, fluorescent lamps etc. Nowadays it is still used (illegally) in Artisanal and Small-scale Gold Mining (ASGM).

A global pollutant

Large amounts of mercury are still being released into the environment as a result of human activities. Via sediments and water, these can in turn be consumed by animals and travel up the food chain. This ingestion can cause serious harm to humans. The toxic effects include damage to the brain, kidneys and lungs. Mercury poisoning can result in several diseases, including Minamata disease. The phrase “as mad as a hatter” suggests that a person is suffering from insanity. Men working in the hattery business used mercury in the past. The accumulation of mercury in their bodies caused many symptoms, including mental problems.

The main mercury-related challenges:

  • It is a global pollutant due to its widespread presence and use
  • The global cycle, release pathways, destinations and transport are complex
  • Its persistence, bioaccumulation and biomagnification: the concentration of mercury increases as it moves from one trophic level to the next
  • As mercury is highly toxic (methylmercury), it has a negative effect on human health and the environment
  • The element is widely present in the environment and is difficult to remove


Sites contaminated with mercury

The following distinction between sites contaminated with mercury can be made:

  • Chemical industry (e.g. production of chlor-akali and acetaldehyde)
  • Manufacturing industry (e.g. production of batteries (including recycling), lamps, electrical switches, cosmetics and pesticides)
  • Large-scale facilities emitting, using, or recovering mercury (e.g. coal-fired incineration plants, waste incineration, metal recovery, mining, wood impregnation)
  • Small-scale facilities using mercury and materials containing mercury (e.g. dental amalgam and sites linked to small-scale gold mining)


International ambition regarding to Mercury

Minamata Convention on Mercury

Severe events in the past, such as the human and ecological disaster at Minamata Bay in Japan, led to the signing of the “Minamata Convention on Mercury” in 2013. This global treaty aims to protect human health and the environment from the adverse effects of mercury. The treaty came into force on 16 August 2017.


The Minamata Convention will require signatory nations to:

  • Phase out mercury in manufacturing processes (acetaldehyde production by 2018 and chlor-alkali production by 2025)
  • Reduce and, where feasible, eliminate the use of mercury in other industries, such as artisanal gold mining, and reduce emissions to the air from point sources such as coal burning, cement production, smelting of non-ferrous metals and waste incineration
  • Phase out or reduce mercury use in products
  • The Convention also addresses the historic use of mercury, as each signatory nation must develop appropriate strategies to identify and assess sites impacted by mercury or mercury compounds
  • The Convention also addresses the supply and trade of mercury, and safer storage and disposal


The 4th meeting of the Conference of the Parties, COP4, is planned to take place on Bali from 1 to 5th November 2021. Click here for more information about the convention and the COP4.

EU Water Framework Directive

In the Water Framework Directive, mercury and its compounds are classified as priority hazardous substances under the Environmental Quality Standards Directive (EQSD: Directive 2008/105/EC amended by Directive 2013/39/EU) as they bioaccumulate readily, are highly toxic and persistent. Click here for more information about European legislation related to mercury contamination.

Chlor Alkali BREF

Since the implementation Chlor Alkali BREF, mercury cell technology can no longer be used in EU-based chlor-alkali sites beyond 11th December 2017. The Chlor Alkali BREF also addresses the decommissioning of mercury cell plants and the remediation of chlor-alkali production sites.

Industrial Emission Directive for Soil and Groundwater baseline reports

The Industrial Emissions Directive (IED), which was adopted on 24 November 2010, is the main EU instrument regulating pollutant emissions from industrial plants. The IED is based on an integrated approach, the use of the best available techniques, flexibility, inspections and public participation. It approves, on behalf of the EU, the Minamata Convention on Mercury. This global treaty aims to protect human health and the environment from the adverse effects of mercury.

Future development regarding to Mercury

In Europe, sites contaminated with mercury will enter the risk management/remediation phase, after completion of the baseline characterisation phase and the dismantling phase in the case of some chlor-alkali sites.

Many sites have completed the containment phase. This consists of containing groundwater plumes within the site limits and relooking for the development of new remediation technologies to invest in the remediation phase from a sustainable point of view.

Looking ahead, sediments will most likely be a new scenario. This will involve the implementation of innovative investigative technologies, data management and sustainable approaches to the remediation of complex liabilities. 



Mercury Impacted Sites - Call to action on abandoned Chlor-alkali sites

In this background article TAUW provides more in-depth information about the steps needed to manage mercury contamination at abandoned Chlor-alkali sites. We address the complex issues associated with dismantling and cleaning the structures, remediation of the soil and revitalisation of these locations. In addition, we outline an example of the demolition of Chlor-alkali sites in Europe, which can also be copied for sites in countries with economies in transition.

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Our expertise in Mercury

TAUW has extensive experience in consultancy related to managing contaminated sites in a sustainable manner. This includes consultancy services for large-scale and small-scale site assessments, remediation designs, remediation management and monitoring and aftercare campaigns for sites contaminated with mercury across Europe. As a European frontrunner in this area of expertise, TAUW uses innovative approaches to investigation and remediation and always focuses on tailor-made solutions that take account of future legislative developments. We continuously seek a balance between applying the best available techniques, costs and risk reduction.

Mercury in soil and groundwater 

Metals were and are used for all kinds of purposes. Mercury is one of them but more and more phased out because of its toxicity. Before, the adverse impact of mercury was unknown, it was used in several products, in a variety of industrial processes and used in crop protection products. This has led to emissions into the environment and consequently to exposure of human and the ecosystem.

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