The environmental risks of reliance on coal

24 January 2012

Droplets has previously commented on the narrow-sightedness of reliance on coal as an energy source.  Of course then came the incident in Japan and gave the nuclear fear-mongers more ammunition.  Coal mining is also environmentally-dangerous, very dangerous in fact.

In a recent report published in the US b y the USGS, readers learnt that:

Mercury loads in lakes near U.S. cities are four times greater than in rural waterways.

USGS said the study is the first to examine the difference in mercury levels between lakes close to urban centers — where emissions from coal-fired power plants would be expected to be higher — and those in rural areas. The study was published in the journal Environmental Pollution.

Researchers examined atmospheric deposition of mercury — the transfer of the toxin from air to water or earth — by comparing lake sediment within 30 miles of cities to sediment from lakes more than 90 miles away from urban areas.

“With all of the environmental issues requiring attention, this study is an excellent example of how science can help target our attention and actions to geographic areas where mercury’s toxic impacts are likely to be the greatest in the near term on both ecosystems and humans,” USGS Director Marcia McNutt said in a statement.

The study comes as U.S. EPA is expected to release the nation’s first standards for mercury and other air toxic emissions from power plants this week (see related story). The agency has reportedly signed the final regulations but at press time had yet to make them public.

Coal-fired power plants and industries are among the primary sources of mercury emissions in the country. Once the mercury leaves the plants, it can end up in lakes through wind patterns or falling in precipitation. Mercury can also contaminate lakes through runoff.

Atmospheric deposition is the predominant way mercury emissions reaches ecosystems, where it can accumulate in fish, other wildlife and humans.

“This finding could have important implications for management of mercury emissions to reduce the risks mercury poses to humans and wildlife,” USGS scientist Peter Van Metre, the author of the study, said in a statement. “The results illustrate the importance of reducing mercury emissions in the U.S. and not focusing only on emissions globally.”

Researchers found, for example, that mercury deposition to South Reservoir, a lake 6 miles north of Boston, was five times higher than what was found in Crocker Pond, which is 130 miles north in western Maine. USGS said such a pattern repeated itself elsewhere.

The research comes after a comprehensive study in October on mercury in the Great Lakes, which are close to several cities with large coal-fired power plants. Researchers for that study found that mercury contamination in the Great Lakes region is on the decline but that on average mercury concentrations in game fish exceed levels that pose a risk to human health.

In addition to toxic issues, coal mining constitutes a massive and direct physical threat to the environment, including water resources.  In South Africa, for example,

Significant developments in the energy sector are underway in western Limpopo because of the extensive coal resources in that region. Besides the South African electricity company Eskom’s massive Medupi power station, near the existing Matimba power station, there are several other mega-projects in the pipeline. The question is whether these are sustainable or in some cases, even viable.

Against the background chatter about nationalisation and environmental sustainability, South Africa needs to carefully consider the continued development of its vast mineral resources. While our national wealth has historically been underpinned by mineral extraction, the question is not only how we can continue to extract this wealth with the broadest social benefit, but perhaps more importantly, how we can do so without destroying the very systems we rely on to sustain us.

Nowhere in South Africa are these issues more apparent than in western Limpopo, a region mired in poverty and plagued by water scarcity. The biggest single constraint to the exploitation of these coal resources is the lack of water in the region.

West Limpopo is the most water stressed region of the country if this is measured using the globally accepted method of ‘water crowding’, which considers the number of people against the available water supply. A water-crowding index in excess of 2000 is considered environmentally and socially unstable. The index in Limpopo was already at 4219 a decade ago. The problem has worsened since then.

Moses Madau, of Dzomo la Mupo, a local environmental group, summed up the general feeling when he said that there was deep resentment and concern at the alleged statement by CoAL at a recent meeting that the scarcity of water would not affect this generation, but only the coming generations. This is the very definition of unsustainable.

Read the full article here.

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