Tree rings reveal the reduction of Cd, Cu, Ni and Pb pollution in the central region of São Paulo, Brazil - Locosselli, Giuliano Maselli; Chacón-Madrid, Katherine; Arruda, Marco Aurélio Zezzi; Camargo, Evelyn Pereira de; Moreira, Tiana Carla Lopes; André, Carmen Diva Saldiva de; Andre, Paulo Afonso de; Singer, Júlio da Motta; Saldiva, Paulo Hilário Nascimento; Buckeridge, Marcos (Environmental Pollution, 2018)