EVALUATION OF TRACE METALS AND MAJOR IONS CONCENTRATIONS IN RAINWATER IN DOWNTOWN SAO PAULO CITY

Rainfall samples collected in the downtown area of Sao Paulo city, during 2003, exhibited average concentrations of cadmium, lead and copper of 1.33, 8.52 and 49.5 nmol L-1, respectively. Among the major ions, NH4+ was the predominant species followed by NO3-, SO42- and Ca2+, with volume weighed mean (VWM) concentrations of 37.1, 20.1, 11.9 and 10.8 mu mol L-1, respectively. All the determined species showed high inter-events variability, including free H+ ions whose VWM concentration was 4.03 mu mol L-1, corresponding to a pH value of 5.39.