Chemical composition of bulk precipitation in the metropolitan area of Costa Rica, Central America

Trace metals and inorganic ions were measured in bulk precipitation sampled at eleven sites in the metropolitan area of Costa Rica. The ions were analyzed by ion chromatography, and the trace metals by atomic absorption spectrometer with a graphite furnace attachment. The results indicated that Na+ and SO42− were the most abundant ions, and of the metals, that Al and Fe had the highest concentrations.Spearman's correlation applied to all data showed a high correlation among SO42−, NO3− and NH4+, indicating a common anthropogenic origin. In addition, the correlation found between Na+, K+ and Cl− indicated a sea aerosol contribution. High positive correlations between trace metals were found for Al–Mn, Ni–Mn, Ni–Al, Cu–Ni, Pb–Cu, Pb–Ni and Pb–Mn.