By Valerie Volcovici

WASHINGTON (Reuters) -About 40 federal government employees who worked on coal-mining and firefighter safety before their jobs were eliminated were asked to return to work this week, although it’s unclear if their positions will be permanently reinstated, West Virginia’s senator and the agency’s union said on Tuesday.

The employees are from the National Institute for Occupational Safety and Health, part of the Health and Human Services Department, and worked on coal miner health and firefighter fatality prevention programs.

They were put on administrative leave earlier this month as the Trump administration eliminated most of NIOSH’s 1,000-person workforce. Reuters reported the move cut key safety programs for coal miners, who have seen a resurgence in black lung disease. The staff were scheduled for termination June 2.

The union, AFGE Local 3430, welcomed the temporary call-back, which it said focused on the NIOSH units "currently in the media spotlight" but called on HHS to bring back all NIOSH employees, saying they are vital in protecting workers in high-risk industries.

The two programs previously had about 40 staff members and virtually all of them were asked by regional managers to return from administrative leave this week, although they are still due to be terminated on June 2, according to AFGE Local 3430, the agency’s union.

West Virginia Senator Shelley Moore Capito has lobbied HHS Secretary Robert F. Kennedy Jr. to restore the programs, including the coal-focused work of its Morgantown, West Virginia office.

She was encouraged by the news but wanted more clarity about the agency’s future. "My understanding is that this is temporary so my focus will continue to be on working with @HHSGov on permanently restoring these functions and personnel in the most efficient and effective manner,” she said in a statement.

HHS did not immediately respond to a request for comment.

Scott Laney, who lost his job as a coal-surveillance epidemiologist in the NIOSH reduction-in-force, told Reuters that regional managers verbally asked him and others at the Morgantown office to return from administrative leave.

The managers did not say if his job would continue past June 2 or send written notification, making him question whether the agency was reversing the job cuts.

Laney said he was scheduled to testify at a District Court hearing on May 7 in a case against Kennedy over the job cuts affecting NIOSH’s West Virginia office.

President Donald Trump signed executive orders aimed at reinvigorating the U.S. coal industry.