Large benefits can be achieved for society by reducing global emissions of mercury. Global savings of US$1.8-2.2 billion (EUR1.3-1.6 billion) can be made by reducing damage to IQ alone, according to recent research.
Mercury emitted to the atmosphere primarily comes from combustion of fossil fuels (about 46 per cent of global mercury emissions) and high temperature processing of minerals, such as non-ferrous metal ore smelting from iron and steel foundries and the cement industry.
Mercury can remain in the atmosphere for a long time and can be transported to regions far from the source of emission. Once deposited, it can be taken up by living organisms and enter the food chain. Bacteria in aquatic systems convert mercury into methyl mercury (MeHg) which bioaccumulates in fish in levels which are dangerous to other living organisms, including humans.
Methyl mercury (MeHg) affects the nervous system and is distributed by bloodstream around the body, including the brain and the placenta. The effect on developing foetuses is of particular concern because MeHg can be passed on from pregnant women to the unborn child. Populations who eat a lot of fish containing high levels of MeHg are especially at risk.
Exposure of children to MeHg has been shown to result in reduced IQ. Reduced IQ can have an economic impact through job attainment and performance, as well as educational achievement, which, in turn, affects earnings. By using a decrease in IQ as a measure for damage to human health, the researchers estimated the costs to society from mercury pollution. The cost to society was calculated in terms of the dose of MeHg inhaled in contaminated air and from eating polluted food. This was then compared with the economic benefits achieved from introducing mercury emission control measures in different future scenarios.
Technical and non-technical emission reduction measures could reduce mercury emissions below 2005 levels by 2020. In the study, three mercury emission scenarios were investigated. Under status quo conditions, current legislation would continue until 2020, resulting in an increase of mercury emissions of about 25 per cent. Under the EXEC (Extended Emissions Control) scenario, total mercury emissions could be reduced by a third compared to 2005 levels and under the MFTR (Maximum Feasible Technological Reduction) scenario, 2005 emissions could be reduced by up to 50 per cent.
Annual damage costs due to IQ loss from ingesting methyl mercury were estimated to be US$2.9 billion (EUR2.1 billion) caused by non-intentional emissions of mercury (e.g. as a by-product from power plants, smelters and kilns) and US$0.8 billion (EUR0.6 billion) from emissions due to its intentional use in products.
The corresponding damages from inhalation of mercury were estimated to be US$2.9 million (EUR2.1 million). This is a small fraction of the costs associated with eating food contaminated with mercury. However, the researchers point out some population groups, such as small-scale gold miners, would be particularly affected and could suffer more serious health problems with correspondingly much higher damage costs.
By 2020, the study suggests the introduction of emission reduction measures could reduce the damage costs to society under the EXEC scenario compared with the status quo by more than half and produce societal benefits of around US$1.8 billion (EUR1.3 billion) annually. Additional benefits of US$0.4 billion (EUR0.3 billion) could be achieved under the MFTR scenario.
Source: Sundseth, K., Pacyna, J.M., Pacyna, E.G., et al. (2010). Economic benefits from decreased mercury emissions: Projections for 2020. Journal of Cleaner Production. 18: 386-394.