The Environmental Protection Agency continues to go through administrative motions suggesting it's serious about removing lead from avgas. Earlier this month, the agency sent a draft endangerment finding to the White House as part of its proposed action to address a petition from Friends of the Earth claiming that lead in avgas represents a public health risk.
Before it can move forward, the EPA has to issue a finding under terms of the Clean Air Act that health risks actually exist. To reach that finding, the agency has ordered lead pollution studies around a number of U.S. airports. Friends of the Earth has asked EPA to ban lead from avgas "without delay," although the industry still has no ready high-octane substitute for 100LL.