The U.S. Environmental Protection Agency took the first step toward setting stricter emissions standards for heavy-duty trucks—an out-of-character move for the same agency dead-set on undoing clean car standards. The EPA’s plan would reduce nitrogen dioxide emissions, which contribute to smog and particulate matter and are linked to respiratory illnesses and premature death. But we’re holding our applause. Not only could the agency's standards, once officially proposed, fall short of what public health experts say is truly needed to protect human health, but some suspect that they could be a way to preempt stricter standards expected to come from the states. In that way, the agency is in fact shielding the trucking industry from necessary stronger protections down the line. The move may be another play in the ongoing fight over California’s right to set better standards than the federal government.