Australian emissions of atmospheric mercury from natural and anthropogenic sources

Estimates of anthropogenic and natural mercury (Hg) emissions from Australia in 2001 suggest that total anthropogenic emissions were about 10.2 tonnes, principally from fossil fuel combustion. An additional 2.6 tonnes of mercury may have been released from combustion of vegetation in wildfires (often caused as a result of human intervention), burning as part of fuel reduction/regeneration programs and burning carried out during land clearing and agricultural practices. Mercury derived from natural sources (including re-emission) was estimated to be in the range 130-270 tonnes/ annum, with the lower value probably being more reasonable. Mercury emission inventories are subject to large uncertainties. According to the latest global anthropogenic mercury emission inventory, Australia is suggested to emit >102.5 tonnes Hg/yr, which is 10 times more than that confirmed by this study. This discrepancy arises by the use of inappropriate mercury emission factors, particularly for the combustion of Australian coals, in the global estimate.6 page(s