The tests, scheduled for April 7–19, will be free of charge to miners in Randolph, Upshur, Webster, Nicholas and Fayette counties in West Virginia.

The full plan for screenings includes 16 counties, including the above and Wyoming, McDowell, Boone, Logan, Mingo, Wayne, Kanawha, Grant, Harrison, Barbour and Preston counties.

The specific locations for the tests have not been determined, but the agency said its state-of-the-art mobile van will be set up at convenient community locations for workers to receive his or her confidential screening, a process which takes about 30 minutes.

All active workers are eligible for a free test under the regulations of the Federal Mine Safety and Health Act of 1977, and the mobile van's screening includes a chest X-ray, breathing test and one-on-one interview with an agency expert to review any potential health issues.

“NIOSH provides the individual with the results of his or her own screening, but by law each person's screening remains confidential," the agency said.

“No individual information is publicly disclosed, including the names of participating miners."

NIOSH director John Howard noted the vital nature of the testing for workers because early detection is key to treatment, and in many cases the condition – which is caused by inhaling coal dust – shows few to no symptoms in the early stages.

“Much like any other physical check-up, the NIOSH health screening involves minimal time and effort by participants,” Howard said.

“The results of this minimal investment can be critical for miners' health, quality of life, and family peace of mind."

While not curable, the disease is preventable, NIOSH noted.

“Miners who participate in health screening have the best chance for detecting any injuries to the lungs at an early stage, when steps can be taken to reduce further exposures to coal mine dust and prevent the disease from progressing," the agency said.

The black lung rate in the US is currently 9%, but West Virginia miners are being more heavily afflicted with a 13% average, NIOSH said.

It has set up a website for workers and their families to find out more about the condition and the agency's program. For further information visit: http://www.cdc.gov/niosh/topics/surveillance/ORDS/ecwhsp.html.