NEW YORK — Government staffing cuts have gutted a small U.S. health agency that aims to protect workers, drawing rebukes from firefighters, coal miners, medical equipment manufacturers and others.

The Cincinnati-based National Institute for Occupational Safety and Health, part of the Centers for Disease Control and Prevention, is losing about 850 of its approximately 1,000 employees, according to estimates from a union and affected employees. Among those ousted were its director, Dr. John Howard.

The layoffs are stalling — and perhaps ending — many programs, including a firefighter cancer registry and a lab key to certifying respirators for many industries.

The cuts are “a very pointed attack on workers in this country,” said Micah Niemeier-Walsh, vice president of the union local representing NIOSH employees in Cincinnati.

Unions that represent miners, nurses, flight attendants and other professions have criticized the cuts, saying it will slow the identification and prevention of workplace dangers.

NIOSH doctors review and certify that 9/11 first responders who developed chronic illnesses could qualify for care under a federal program, noted Andrew Ansbro, president of a union that represents New York City firefighters.

“Dismantling NIOSH dishonors the memory of our fallen brothers and sisters and abandons those still battling 9/11-related illnesses,” Ansbro said in a statement.

NIOSH was created under a 1970 law signed by President Richard Nixon. It has done pioneering research on indoor air quality in office buildings, workplace violence and occupational exposure to bloodborne infections.