Outdoor particulate matter exposure and lung cancer: A systematic review and meta-analysis - Hamra, Ghassan B.; Guha, Neela; Cohen, Aaron; Laden, Francine; Raaschou-Nielsen, Ole; Samet, Jonathan M.; Vineis, Paolo; Forastiere, Francesco; Saldiva, Paulo Hilário Nascimento; Yorifuji, Takashi; Loomis, Dana (Environmental Health Perspectives, 2014)