Employees at the Department of Health and Human Services began to receive notices of mass layoffs on Tuesday, days after HHS Secretary Robert F. Kennedy Jr. announced that 10,000 people would lose their jobs, including employees working on tobacco use, mental health and infectious disease.

The layoffs are expected to impact 3,500 employees at the Food and Drug Administration and 2,400 employees from the Centers for Disease Control and Prevention -- nearly one-fifth of the workforce at both public health divisions, which fall under HHS.

In total, and including roughly 10,000 people who have left over the last few months through early retirement or deferred resignation programs, the overall staff at HHS will fall from 82,000 to around 62,000 -- or about a fourth of its workforce.

As news of the cuts spread, employees stood in long lines outside of their offices in Washington, D.C., Maryland and Georgia, some waiting for hours as security determined whether they could be let in the building or not. In some cases, employees were turned around after being informed that they no longer had a job.