Air pollution and emergency room visits for pneumonia and influenza in elderly people in Sao Paulo city - Brazil - Martins, L. C.; Latorre, Maria do Rosário Dias de Oliveira; Braga, A.; Cardoso, Maria Regina Alves; Gonçalves, F. L. T.; Saldiva, Paulo Hilário Nascimento (ISSE - The Thirteenth Conference of the International Society for Environmental Epidemiology, 2001)