The potentially fatal disease is caused by the inhalation of coal dust over a long period, and can emerge up to 15 years after exposure.
A coalminer diagnosed with the first case of black lung in Australia in more than 60 years worked in an underground mine for six years after early signs of the disease were missed in a medical examination.
The department last year admitted 150,000 x-rays were still awaiting database entry, the ABC reported.
The CFMEU’s safety and health officer, Jason Hill, said claims that the disease was eradicated 30 years ago thanks to safer mining practices were rubbish.
A 1984 government survey identified 75 confirmed or suspected cases of black lung in Queensland’s coalmining workforce.
Queensland coal companies had nominated 265 doctors to supervise health checks for their miners, the ABC said.
But there are concerns local radiologists don’t have the expertise to detect black lung disease.