Coal Services Standing Committee on Dust Research and Control produced the booklet to promote a better understanding of the health effects and control of airborne dust. The booklet, aimed at the entire workforce, cuts through the technical speak around underground coal dust.

The Coal Mine Health and Safety Act Regulation 2006 defines airborne dust to include both respirable (invisible) dust and inhalable (visible) dust.

Unlike larger dust particles, which are stopped by the nose or mouth, respirable dust and quartz particles (which are only a fraction of the width of a human hair) can be retained in the lungs causing all sorts of respiratory problems down the line.

New South Wales’ regulations state the concentration of respirable dust should not exceed 2.5 milligrams per cubic metre during a sampling period. The concentration of respirable quartz dust should not exceed 0.12mg/cu.m in underground coal mines.

The booklet advises coal miners that if they suspect they have been “dusted”, they should request to see a Coal Services Health doctor or their own GP.

“One of the key factors involved in the onset of lung dust disease is the total amount of coal dust or quartz that a person has inhaled during their working life. It is not based on whether the person has been exposed to a high level of dust in a single event on one part of a shift, or due to a particular mining method,” the booklet states.

Coal Services has found the most effective methods of dust control are adequate ventilation and the application of water, in sufficient quantity, and in the correct location. It does note water sprays are useless unless they are operating effectively.

Dust capture by using scrubber systems at certain points, such as continuous miners and longwall BSL crusher and discharge-to-conveyor-belt, are also important.

In continuous miner panels, ventilation must be maintained at the face by erection of tightly fitting brattice or ducting which should be extended systematically so that mine workers are never working ahead of the ventilation.

The booklet states one of the worst mining practices causing high-dust results is working inbye ahead of the ventilation ducting or brattice.

Another bad mining practice causing high-dust results on longwalls are people working on the return side of the shearer.

On contact with quartz, Coal Services said the most common exposures occur when cutting stone roof or floor or stone bands in the seam during continuous miner or longwall operations; roof bolting or drilling into sandstone or mudstone and dry drilling; at material transfer and loading points and in ventilation returns.

Research has found one of the worst mining practices causing high-quartz results is cutting or drilling of stone bands, rolls and/or roof.

The new booklet is being distributed by Coal Services’ environmental monitoring technicians (dusties) when they attend mine sites to undertake dust sampling. Copies of the booklet will also be distributed through the Mines Rescue and Coal Services Health induction and refresher training courses and can also be found on Coal Services’ website.

Managing airborne dust

Isolation/capture of dust sources via sealing of transfer points, BSL, crushers

Water sprays at appropriate locations, close to breakage point with sufficient water volumes, pressure and jets

Correct ventilation quantities and location, advance ventilation ducting/brattice to standard

Regular maintenance of dust-suppression equipment

Operator positioning, job rotation, automation and wearing PPE

Control of dust levels along travelling roads