On May 24, 2010, the Environmental and Energy Study Institute (EESI) held a briefing on the public health implications associated with different energy sources and technologies. Energy and climate legislation pending before Congress aims to enhance U.S. energy security and reduce greenhouse gas emissions, while minimizing energy costs. Energy choices, however, can carry significant costs that are not directly reflected in prices paid by consumers. Health impacts can add substantial hidden costs to the total “price” of energy — with costs accruing to families, businesses, and the economy as a whole. This briefing examined recent research on the nature and magnitude of these health costs, and discussed their implications for federal energy policy.