The agency is closing the Office of Research and Development, which analyzes dangers posed by hazards including toxic chemicals, climate change, smog, wildfires, water pollution and more.

Justin Chen, president of the American Federation of Government Employees Council 238, the union representing 8,000 EPA workers nationwide, said the organizational structure of ORD put barriers between the agency’s researchers and the agency’s political decision-making, enforcement and regulatory teams—even though they all used ORD’s work.

The Environmental Protection Agency is eliminating more than 500 employees from its research and development arm.