Vehicular emission factors and chemical profile of particulate matter measured in two road tunnels in the Metropolitan Area of Sao Paulo, Brazil - Nogueira, Thiago; Miranda, Regina Maura; Dominutti, Pamela Alejandra; Hetem, Ivan Gregório; Fornaro, Adalgiza; Andrade, Maria de Fátima (AGU Fall Meeting 2013, 2013)