Tuesday, 26 March 2002
Charcoalition spokesperson Chris Kowal said “A University of Calgary Faculty of Medicine research team has recently found that exposure to mercury causes degeneration of brain neurons in animals, whether it is inhaled as vapor or consumed in the diet as a food contaminant.”
“Mercury in the ground is taken up by trees and other vegetation and remains there until the vegetation rots or is burned. Mercury was extensively used in the gold mining activities in many of the forests in the South Coast region of NSW and it is likely that many of the trees used in the charcoal factory would contain substantial amounts of mercury. When these trees are burned, the mercury vaporises, releasing a very dangerous form of mercury into the atmosphere.”
The University of British Columbia, published a paper called ‘Mercury Pollution from Deforestation’, which provides an insight into the mercury levels that might be found in vegetation near gold-mining activities where mercury was used, and the amounts released in vegetation combustion.”
Chris concluded “With respect to the charcoal plant, mercury vapour emissions will be highly concentrated in the region because of the 200,000 tonnes of timber being burnt annually on site. We call on Planning NSW to include this issue as part of the assessment process, in particular, the mercury content of trees destined for the charcoal plant, the amount of mercury vapour that would be emitted from the retorts, and the health impacts of such emissions.”
Mercury was used in gold mining operations for the separation of fine gold particles through amalgamation then burning. Elmer Diaz, University of Idaho, states “during the amalgamation process, a good amount of metallic mercury is also lost to rivers and soils through handling under rough field conditions and to volatilization. In addition, Mercury rich tailings are left in most mining sites … It is expected that soils around mining sites should also be contaminated.” Up to 87% of the mercury used vaporises and is dispersed into the atmosphere, being deposited onto forest soils and rivers, to be absorbed by vegetation.
New Scientist magazine 08/09/2001 reports that according to the National Centre for Atmospheric Research in Colorado, “about 95% of the mercury stored harmlessly in the forest is spewed back into the air when the trees are burned. About 12% of mercury in the atmosphere probably comes from such fires.”
Gold mining activities aside, the University of British Columbia reports that ALL trees contain some mercury – the natural mercury level in forest ecosystems is 0.001 to 0.3 ppm.
Just looking at the Bega region – according to a Bega Metallogenic Map and Mine Data sheets, 1978, there were 318 registered mines from the Victorian border to Bingi. 227 of these were registered as mining gold. Less than 20 of these mines were in an alluvial geological setting, the rest were mainly shaft mines, with a few open-cut and shallow pit operations. Many of these 227 mines would have used mercury.
Some mercury is present in the trees that will be burned by the charcoal plant. All mercury in these trees will be vaporised then emitted into the atmosphere. There appears to be an oversight in the EIS because there is no mention of mercury emissions in the document.
The Charcoalition has called on the NSW Government to include this issue as part of the assessment process. In particular, the mercury content of trees destined for the charcoal plant, the amount of mercury vapour that would be emitted from the retorts, and the health impacts of such emissions.
If the flames don’t get you, the poison will
New Scientist magazine, vol 171 issue 2307, 08/09/2001, page 23 states that Hans Friedli and his colleagues at the National Center for Atmospheric Research in Boulder, Colorado, burnt soil and tree samples and reckoned that about 95 per cent of the mercury stored harmlessly in the forest is spewed back into the air. About 12 per cent of mercury in the atmosphere probably comes from such fires.