After months of often-bitter wrangling, employes at the National Institute for Occupational Safety and Health (NIOSH) in Rockville have been ordered to leave town.

The Reagan administration announced in June, 1981, that 110 of NIOSH's 176 employes in Rockville would be reassigned to Atlanta and the rest to NIOSH research facilities in Cincinnati. The move made sense, Health and Human Services Department officials said, because NIOSH is the research arm of the Centers for Disease Control, which is based in Atlanta.

The Rockville employes thought otherwise. Local 41 of the American Federation of Government Employes contended that the move was designed to dismantle the business-watchdog agency and was ordered because the new NIOSH director, J. Donald Millar, lived in Atlanta and didn't want to move.

A congressional attempt to make NIOSH part of the Bethesda-based National Institutes of Health failed in September, and Congress dropped a restriction during its lame-duck session that had prohibited HHS from spending any money to make the move.

NIOSH employes were told after Christmas to report to Atlanta by Jan. 31, prompting union complaints that the date was unfair. Both sides asked the Federal Service Impasses Panel this week to help them resolve the disagreement. Meanwhile, some employes are hoping Congress will intervene once again.

Only 63 NIOSH employes remain in the Rockville office. Less than a handful of the employes moved to Atlanta. About 100 others have left the agency.