Tag Archives: mercury emissions

Cutting Trees, Digging Gold and Mercury Pollution – Amazon

The past two decades have seen a sharp increase in illegal and informal gold mining in Peru‘s southern Amazon region of Madre de Dios. These small-scale operations typically involve cutting down all of the trees in a particular area, digging a large pit and then using mercury to extract gold from the excavated soil… The mercury binds to any gold in the soil, creating a large chunk that can be easily removed. This chunk is then burned, evaporating and releasing the mercury into the air while leaving behind pure gold

Besides releasing mercury into the atmosphere, miners typically add three to four times more mercury… than is actually needed. While this ensures all of the gold is extracted, it also means there is a large amount of leftover mercury in the slurry that is inevitably dumped back into the excavated pit. And because the whole process started with the clearing of trees, there’s nothing to stop the mercury-laden soil from eroding into nearby rivers.

“This means mining practices can hit people three times with mercury — once from direct contact, once from atmospheric transport and deposition, and once from soil mercury mobilization due to land clearing,” said William Pan,Professor of Population Studies at Duke. “The scenarios we run demonstrate that even if mining were to end today, since vegetation is unlikely to return for several decades, the cleared land will continue to release mercury.”

For more details see Duke University

Excerpts from Deforestation, erosion exacerbate mercury spikes near Peruvian gold mining, Science Daily, Dec. 12, 2019

Lead and Mercury in the Seas

The levels of lead and mercury in the sea reduce noticeably following concrete actions to limit their release, recent research at the IAEA using nuclear techniques has shown. The banning of leaded petrol and the closure of a mercury discharging plant have led to decreases in pollution levels over 10-15 years.

This is the case for lead, which when consumed by fish which is in turn eaten by people, can cause damage to the human nervous system and internal organs. Many different activities such as mining or smelting in metallurgy and the burning of coal as well as lead’s use in batteries, paint, ceramics and other everyday items can release it into the environment. The biggest source of lead pollution in the last century was related to the use of leaded petrol.

As part of efforts to develop new methods to determine the source and levels of lead pollution, researchers at the IAEA Environment Laboratories analysed sediments from the Baltic Sea and the Caribbean Sea. In mapping the pollution history in a sediment core from the Baltic coast of Germany, researchers could clearly observe that within 10 to 15 years of phasing out lead in petrol by 1996, lead pollution levels in the sea had decreased..

In addition, IAEA researchers have successfully developed methods to use lead isotope ratios to determine the source of lead pollution and assess whether it is naturally present or the result of anthropogenic activities, since natural and anthropogenic lead sources will show different isotopic fingerprints and isotope compositions….

IAEA scientists’ analysis of a dated sediment core in a Caribbean bay shows total mercury (Hg) levels rapidly decreased after the closure of a discharging plant…Mercury was used in an alkali plant there as a catalyser, and in the 1970s, high concentrations were found in water, sediments and marine organisms as a result of discharges from the plant.  Years later, after the plant had been closed, IAEA researchers showed, by analysing sediment core taken from the bay, that levels of total mercury had started to decrease.  While remnants of this pollution are still buried in the sediment, acute toxicity has been greatly reduced.

Excerpts from World Oceans Day 2018: Regulating Lead and Mercury Releases has Decreased Marine Pollution, IAEA Press Release, June 8, 2018

Boycotting Coal

Chinese coal  consumption dipped by 1.6% in 2014, despite economic growth of 7.3%. The country’s voracious appetite for steel is peaking, damping demand for coking coal. Worries about pollution mean that demand for thermal coal, as used in power stations, is slackening too. Water conservation is another concern for policymakers—on current trends coal could account for a quarter of China’s water use by 2020 and coal reserves are mainly in the most parched regions. Its coal-fired plants are running at only 54% of capacity, a 35-year low. In Beijing two big coal-fired plants closed this week; the capital’s last one will shut down next year.

Another prop to demand has been power generation in rich countries. But in America coal now struggles to compete with natural gas, which has fallen by 80% in price since 2008. Domestic coal use there peaked in 2007. European consumption soared after Germany’s hasty decision to close its nuclear-power plants. But gas and renewables are eating into that.

Coalswarm, an environmental think-tank, says in a new report that two-thirds of coal-fired power plants proposed worldwide since 2010 have been stalled or cancelled…. Overall, Europe and America have already cut coal-fired generation capacity by over a fifth in a decade. The output of American coal mines dropped to 1993 levels in 2013.

Political pressure is growing against the most carbon-intensive fossil fuel. Coal provides 40% of the world’s electricity. But of 1,617GW of global capacity, 75% is of the dirtiest kind…. The chimneys of all but the most modern coal plants also emit plenty of other nasties. Mercury emissions stunt young brains. Sulphur and nitrous oxides scald lungs. Overall, coal kills around 800,000 people a year, most of them poor. In China it is responsible for up to a sixth of the particulates most dangerous for human health.

In America the coal and electric-utility industries are fighting the Environmental Protection Agency’s attempts to curb emissions of CO2, mercury and other toxins contained in coal. On March 25th, 2015 the Supreme Court heard arguments by some state governments, backed by the miners and utilities, that the agency has failed duly to consider the cost of its measures against mercury (see article).

Campaigners reckon 80% of the world’s coal reserves must stay in the ground if the planet is to stand a chance of keeping global warming under 2ºC by 2050. A divestment movement akin to the apartheid-era campaign to boycott South Africa is under way in many universities. Stanford may dump its coal investments and Oxford University is under pressure to do likewise. The World Bank no longer invests in coal-fired plants. Last year Norway’s sovereign-wealth fund dumped its holdings in more than 50 coal companies worldwide. South Korea recently introduced a carbon cap-and-trade scheme which punishes coal….

Furthermore, in some emerging markets, India especially, demand for coal is set to continue rising—so overall global demand may not peak until at least the 2030s. This week India’s government predicted a 19% rise in the country’s coal imports in this fiscal year. But thereafter the plan is to bring in private contractors to develop India’s untapped coalfields, and then to phase out all thermal-coal imports. If so, that will be grim news for the Indonesian, Australian and South African mining firms that are supplying India at the moment.

Even though some other developing nations’ coal imports will grow in future, coal companies are having to face up to a crisis now. Some are cutting costs and getting ready for a wave of consolidation. Others are litigating and lobbying against change.

Excerpts from Coal Mining: In the Depths, Economist, Mar. 28, 2015, at 65