CNN: Six heat-trapping gases that contribute to air pollution pose potential health hazards, the Environmental Protection Agency said Friday in a landmark announcement that could lead to regulation of the gases. “This finding confirms that greenhouse gas pollution is a serious problem,” EPA Administrator Lisa Jackson said. The gases — carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride — have been the subject of intensive analysis …