Senator Tom Carper (D-Del.), Chairman of the U.S. Senate Subcommittee on Clean Air and Nuclear Safety, convened a hearing, "Federal Efforts to Protect Public Health by Reducing Diesel Emissions" on May 12, 2011. The purpose of the hearing was to review health impacts of diesel emissions and federal programs that mitigate diesel emissions. Senator Carper introduced the Clean Construction Act of 2011 earlier that day.