But neither case was the dreaded “black lung” disease, authorities said.

One case relates to a current worker who has been diagnosed with mixed dust pneumoconiosis, the Regulator said. The worker spent much of his career in the NSW coal industry, mostly underground, but has not worked in a production-related position since 2004.

This was just the second case of mixed dust pneumoconiosis reported in NSW since the 1970s – another was detected earlier this year.

The other worker had contracted silicosis.

The mixed dust disease is similar, but differrent, to coal miner’s pneumoconiosis (black lung) according to information from Coalservices. It is caused by a mixture of dust inhalation, mainly coal and crystalline silica. Black lung is caused by coal dust.

The Mercury understands both the mixed dust pneumoconiosis cases have been from the Hunter region. 

NSW Resources Regulator chief compliance office Anthony Keon said both cases were identified through health surveillance screening.

“The priority is to ensure these workers are getting the best possible level of support and care - and ensuring that airborne containments are actively being controlled throughout the NSW mining industry,” he said.

“The Resources Regulator’s Major Investigation Unit is now investigating each case and will look closely to see if there were breaches of the work health and safety laws.

Mr Keon said neither of the miners had worked in the Illawarra coal industry.

“The worker diagnosed with mixed dust pneumoconiosis spent over 30 years working in underground coal mines throughout the Hunter region,” he said.

“The worker diagnosed with a confirmed case of simple silicosis has a varied work history with a combined 14 years in other industries, interstate and overseas, and a combined 10 years at various underground coal mines throughout the state, including the Hunter region.

Queensland has been the epicentre of the re-emergence of black lung disease in Australia, with at least 21 cases diagnosed since 2015.