Industry and Investment NSW has released the results of a study into the levels of airborne dust found at the state’s coal mines.
The investigation revealed that longwall mining operations in Newcastle and the Hunter District had the highest frequency of excessive dust levels.
The studies were designed to test the effectiveness of legislation introduced in December 2007, which required the levels of inhalable dust in coal mines to be limited to 10 mg per cubic metre.
“The results to date indicate that improved dust control measures will be required in the underground coal mines of NSW,” the Government said.
The investigators took a total of 303 samples from longwall operations across the state between February 2008 and September 2009.
Of those, 113 samples, or 37.3%, were in excess of the required limit.
The Newcastle and the Hunter Districts recorded very high non-conformance rates of 42.3% and 52.6% respectively, while 25.3% of the samples from the Southern District were above the limit.
The Western District was the only area to record perfect results, with none of its 29 samples above the limit.
The study also took 894 samples from other underground operations around the state, with 21.8% of those exceeding the limit.
Once again, the Newcastle (28.1%) and Hunter Districts (30.2%) were the worst offenders, with the Southern District (20.2%) not far behind.
By comparison, only 2.1% of 426 surface samples exceeded the level.
According to the Department, the main reasons for the inadequate ventilation, water and dust control, poor operator positioning, damaged equipment and poor work practices.
The Government recommends mines implement dust suppression equipment, like water sprays or isolation or capture technology and make sure they are regularly maintained.
Ventilation also needs to be applied in the correct quantities and at the right locations.