Chemical Composition and Sources of PM10 Particulate Matter Collected in San José, Costa Rica

Measurements of trace metals and inorganic ions were carried out on PM10 aerosols sampled at two sites in the city of San Jose, Costa Rica. Samples were collected with a Thermo Andersen high volume PM10 sampler on glass fiber and quartz filters. The ions SO4 2, NO3 , Cl , F , PO4 3, NH4 + , K + , Na + , Ca 2+ and Mg 2+ were analyzed by ion chromatography and the trace metals V, Cu, Cr, Pb, Ni, Mn, Fe and Al were analyzed using an atomic absorption spectrometer with a graphite furnace attachment. The results indicated that SO4 2 was the most abundant ion, and Al the trace metal with the highest concentration. Pearson's correlation applied to all data showed a high correlation among SO4 2 , NO3 and NH4 + , indicating a common anthropogenic origin. In addition, the correlation found between Na + -K + and Ca 2+ -Mg 2+ indicated a crustal origin. No correlation was found among the trace metals except Cu-Cr and Fe-Cr. The influence of wind direction on trace metal concentrations is also discussed.