Recent levels of respirable dust nearly four times the acceptable limit at a New South Wales open cut coal mine has caused the state regulator to issue a warning to operators.

Dust can wear down equipment, harm vegetation and wildlife, and affect the quality of air, water and soil in an area. But most of all, dust affects the workers on the front lines of the mining industry.

Coal dust is second only to crystalline silica dust in the dangers posed to workers, but a combination of the two can be deadly.

Silicosis caused by silica exposure is estimated to currently affect around 100,000 people in Australia. Left untreated there is very real risk of those affected developing incurable lung diseases.