Emissions of 52 of 93 reported substances decreased in 2009-10, but emissions of cyanide from metal ore mining almost doubled, according to National Pollutant Inventory data released yesterday.
More than 4,200 facilities submitted data on their emissions and waste transfers in 2009-10, with levels of common air pollutants like carbon monoxide, NOx, SO2 and VOCs either steady or decreasing slowly in recent years.
Emissions for particulate matter have remained fairly constant over the last several reporting years and national emissions of lead and its compounds have decreased.
Huge increase in cyanide emissions
The latest data reveals that cyanide is one of the few substances showing a marked increase in emissions in 2009-10, with emissions from all industrial sources rising from 1,200,000kg in 2008-09 to 2,200,000kg.
That's largely due to metal ore mining (a category that encompasses gold mining), which came close to doubling its cyanide emissions to air and land – from 1,067,320kg in 2008-09 to 1,968,100kg in 2009-10.
The bulk of those emissions are to air.
Cyanide emissions from basic non-ferrous metal manufacturing also increased significantly from 2008-09 to 2009-10.
Companies reporting major increases in cyanide emissions in 2009-10 included Kalgoorlie Consolidated Gold Mines, which in 2009-10 reported emitting 370,000 kilograms of cyanide to air from its Fimiston operation located on the edge of Kalgoorlie-Boulder – a massive increase on the 29,000 kilograms it reported in 2008-09.
Emissions to air from its Gidji roaster rose from 110,000kg in 2008-09 to 150,000kg in 2009-10.
Both Fimiston and Gidji also reported rises in discharges of cyanide to water.
Other large increases were reported by Barrick's Kanowna Belle gold operation (air emissions of cyanide rising from 42,000kg to 100,000kg), AngloGold Australia's Sunrise Dam gold mine (which reported an increase in air emissions of 9,000kg to 65,000kg) and St Ives Gold's Widgiemooltha gold operation (130,000kg to 250,000kg).
AngloGold notes in its report that it used a different method for calculating cyanide volatilisation in 2009-10.
Newmont's Boddington gold mine – which began operations in mid-2009 – also reported emitting 280,000kg of cyanide to air in 2009-10.
Cyanide is highly toxic to humans and animals.
