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Fritz Brugger is co-director of the Center for Development and Cooperation (NADEL) at ETH Zurich and a research associate at the Graduate Institute of International and Development Studies (IHEID) in Geneva. The Minamata Convention, a global treaty that aims at protecting human health and the environment from the adverse effects of mercury, has put artisanal and small scale gold mining (ASGM) on the agenda of the international community. Globally, ASGM is the biggest source of mercury emissions. However, in Mozambique coal combustion might soon emit more mercury to the environment than the country’s informal miners.

Mozambique has declared ‘more than insignificant’ ASGM under the Minamata Convention. This self-declaration requires the government to work towards a National Action Plan to promote mercury-free methods, formalise and regulate the sector, inform and train ASGM communities, and develop an ASGM-related public health strategy.

The country’s 65 to 75 000 ASGM miners release between 1.5 and 4.5 tons of mercury per year according to the Global Mercury Assessment. Elemental mercury is used in the ASGM process to form gold amalgam. The most important direct route of exposure is by inhalation when the amalgam is heated to separate the gold. Yet, individuals are also exposed if liquid mercury is not properly stored or if surrounding surfaces have been contaminated. Mercury can further volatilise from contaminated waste materials at mining sites. Because mercury is a persistent substance, it can accumulate in the food chain, inflicting increasing levels of harm on higher order species such as predatory fish and fish-eating birds and mammals.

Mercury is considered by WHO as one of the top ten chemicals of major public health concern. Acute as well as chronic, lower level exposure to elemental mercury have toxic effects on the nervous, digestive, and immune systems and on lungs, kidneys, skin, and eyes.

However, the public health sector in Mozambique is not ready to address mercury related challenges. In a recently completed institutional assessment, we found that the four public health priority areas (community health, occupational health, environmental hazards with health implications, chemicals management) require major efforts to effectively support the mining communities and to protect the wider public.

While the international community gears up support for the ASGM sector in Mozambique, an emerging source of mercury seems to be completely overlooked: Mozambique holds the fourth-largest recoverable coal reserves in the world. According to the Ministry of Energy, Mozambique is set to transform its electricity generation from virtually exclusively hydropower to include about 25% coal by 2025 to cope with the fast-growing demand for electricity; the projects under discussion add anything between 750 and 3870 MW power generation capacity.

Globally, coal combustion is the second biggest source of mercury release with about 475 tons per year. Coal does not contain high concentrations of mercury, but the combination of the large volume of coal burned and the fact that a significant portion of the mercury present in coal is emitted to the atmosphere yield large overall emissions.

Whilst for many major reasons coal is the wrong source of energy for a climate smart future, it is unlikely that the government of Mozambique will deny itself of the use of this relatively cheap and readily available source of energy despite serious health and climate concerns. Projected coal-fired power plants in the vicinity of the towns Tete and Moatize with a joint population of over 300 000 people are a particular public health concern.

Focussing on mercury emissions, we did a back-of-the-envelope calculation using the parameters applied in the Global Mercury Assessment. Our preliminary data show that coal power plants will emit between 0.32 tons (750 MW installed capacity, low level of coal mercury content) and 3.4 tons (3 870 MW and high level of coal mercury content) per year. Taking 2 000 MW capacity and an average coal mercury content as reference scenario, 1.27 tons of mercury will be released to the environment.

Technically, it is feasible to eliminate 95% of the mercury emissions from coal combustion using most recent technology. Increasing power generation efficiency, advanced plant design, and filter technologies can further reduce air pollution and CO2 emissions although it will never make coal combustion a clean technology.

From a regulatory perspective, the challenge is manageable. The number of addressees is small and the policy measures are quite clear. Building technical capacity and procuring the equipment for effective monitoring and enforcement are possible.

Politically, it is a harder sell. The Mozambican government is likely to feel the pressure from investors against stricter environmental regulation, particularly with volatile coal prices. The fear that cleaner coal combustion might translate into more expensive electricity for its electorate and for the local industry might further weaken the appetite for enforcing advanced environmental standards.

While these are notable and important initiatives, donors cannot turn a blind eye to the elephant in the room. It is time to seriously engage with the government in Maputo about the coal industry regulation and reasonable abatement cost per kWh – but also to engage with the investors and technology providers at the domestic front.