EHJ June 2004, pages 194-195
Tina Garrity reports on the EU draft strategy which aims to resolve what should be done with the mounting stocks of mercury that are causing Europe an environmental headache

In the past we have had butter mountains, wine lakes along with surpluses of beef and wheat. Now the problem is mercury, to be exact 11,600 tonnes of it. Stocks have been rising following the development of mercury-free processes in the chlor-alkali chemical sector and the European Commission is not sure what to do with it.

In a bid to tackle the problem, the commission produced a report in December 2002 proposing three solutions for draining Europe's mercury lake: re-use, short-term storage and final disposal. Final disposal is the least environmentally damaging option but appropriate methods are not yet fully developed and costs are relatively high.

Until the technology is in place, the commission is forming an EU mercury strategy to tackle the problem, published in draft from this March for consultation. It covers issues such as current production levels, uses and emissions of mercury, the impact of mercury in the environment, sources of data, international action and options for re-use, storage and disposal.

CONTROLS ON PRODUCTION

Following the publication of a "global mercury assessment" by the United Nations Environment Programme (Unep) in 2002, both experts and stakeholders agree there should be controls on supply and demand. As Europe is a major producer and exporter of the liquid metal, the draft strategy examines how this can be achieved.

Imposing unilateral controls on production is one option. But, claims the commission, other regions will just increase their production to meet global demand. Another possibility is the prohibition of EU exports. This would have the effect of cutting production as there is a current European surplus.

Ultimately, the commission would like to see the EU self sufficient with the surplus meeting EU demand for the next 40 years. However, an international solution is needed as much of the mercury in circulation within the EU comes from imported products. This could be achieved by making the international trade more transparent. Metallic mercury could be added to the prior informed consent procedure for hazardous chemicals and pesticides under the Rotterdam Convention. This would mean that mercury products could only enter Europe with the prior informed consent of the importer. At present, mercury compounds used as pesticides are covered by the PIC procedure, but mercury for industrial use is not. This, however, could only be achieved if parties to the convention from two different geographical regions ban or severely restrict the use of metallic mercury to protect health and/or the environment. The commission is asking member states whether to take unilateral action or opt for the above international approach.

DENTAL AMALGAM

There are currently no EU controls on the use of mercury in dental fillings, which accounted for some 70 tonnes of mercury in 2000. Although work on substitutes is ongoing, there is as yet no consensus that these are an adequate replacement. Some countries have applied national controls. In Denmark, mercury amalgams are only permitted in molar teeth where the fillings are worn. In EU states, dentists should have filters fitted to ensure mercury from fillings are not being released into drains. Amalgam waste from dental care is classified as hazardous waste. A report from the commission has revealed that such practices are lacking in a number of member states, notably the UK, which has been given a formal reprimand.

While there are no overall EU figures for mercury emissions from crematoria, data submitted by nine countries, including the UK, suggests that up to a tonne per year comes from mercury fillings. The signs are this figure is set to increase. Norway and the Netherlands are reporting the increased use of mercury in fillings while France reports a rapid increase in the number of cremation ovens being installed. As with fillings, there are no EU controls on emissions but France, Germany, the Netherlands, Sweden and the UK all report some national controls. The commission is asking whether EU-wide controls should be introduced. Applying abatement techniques such as solid bed filters could reduce mercury emissions by 99 per cent.

COAL COMBUSTION

Coal burning in power plants and for residential heating is the main source of Europe's mercury emissions. Natural mercury comes from volcanoes, evaporation from water and soil surfaces, forest fires and the degradation of minerals. Although coal usage is currently falling, the demand for solid fuel is expected to rise after 2015.

The problem for the commission is that while the larger combustion plants are controlled under the IPPC directive and the large combustion plants directive, there is currently no specific mercury control technique available for this sector.

This may soon change as new techniques are developed. Some mercury can be removed through flue gas cleaning and dust control, so controlling mercury emissions through the large combustion plants directive might soon be an option. Under such a proposal, member states would be allowed to choose an appropriate abatement method. The downside of this is that coal plants would still generate mercury-containing waste so switching to cleaner fuels would be preferable.

A second option is to introduce a mercury emissions trading scheme, such as being proposed in the United States. This could cause difficulties with the IPPC directive, however. Adapting the IPPC directive to allow greenhouse gas emission trading was possible but it might be less acceptable to change it to allow trading for a toxic pollutant like mercury, says the commission.

A third option is pollution charging so that low emitters are rewarded and high emitters penalised. Smaller combustion plants are not regulated under the IPPC and large combustion plants directives but they could be adapted to include mercury emissions, or incentive-based schemes could be introduced for smaller plants.

RESIDENTIAL COAL

Dealing with residential coal domestic combustion is much more difficult. In some regions coal is the only economically available source of heating fuel and in others, such as remote mountain regions or sparsely populated areas, alternative heating systems may not be viable. The problem of residential burning is essentially a local one and mercury is not the major concern, though viewed long term it does contribute to the "global pool". On a more basic level, the enforcement of controls in the residential sector could be difficult. The commission wants to see cities, which have developed their own strategies to deal with low-emission sources sharing the good practice they have developed among other EU member states.

RECOVERY, RECYCLING AND DISPOSAL

The commission estimates that there is currently between 20,000 and 30,000 tonnes of mercury present in products and processes globally. This, along with mercury waste from the chlor-alkali industry, could be recycled, as long as the proper incentives were put in place.

The Spanish state-owned mercury mining company Mayasa is an example of how this could work. It reduces its production of virgin mercury by the amount of recycled mercury it receives. Although this is generally seen as a responsible industry scheme, the commission's directorate general for the environment fears that the recycled mercury will increase consumption and so eventually stimulate demand.

The alternative is to follow the Swedish example and prohibit the re-use of mercury from the chlor-alkali industry. But this still leaves the problem of how to dispose of the surplus. High costs have delayed Sweden permanently disposing of mercury in deep bedrock until 2015, when it is hoped more advanced technology will make it more viable.

The Americans have opted for temporary storage before final disposal. The volume of mercury involved is quite small in relative terms, says the commission - around 1,000m3. The American approach is to store liquid mercury in steel flasks, inside warehouses. The commission asks in its consultation for views on the best approach to take.

European Commission. Development of a EU mercury strategy - invitation to comment. http://europa.eu.int/comm/environment/chemicals/mercury/consultation.pdf