Legal experts say it's a marked departure from the agency’s historic purpose to protect human health and the environment. “It's an all out assault on climate regulation and environmental and public health protections,” says Michael Burger, director of the Sabin Center for Climate Change Law at Columbia University.

Former heads of the EPA warned that President Donald Trump's systematic deregulation is likely to cause serious harm and potentially put lives at risk.

Three former Environmental Protection Agency leaders sounded an alarm Friday, saying rollbacks proposed by EPA Administrator Lee Zeldin endanger the lives of millions of Americans and abandon the agency's dual mission to protect the environment and human health.