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

Abstract

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 chromatogra- phy 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 an- thropogenic origin. In addition, the correlation found between Na + -K + and Ca 2+ -Mg 2+ indicated a crustal origin. No corre- lation was found among the trace metals except Cu-Cr and Fe-Cr. The influence of wind direction on trace metal concen- trations is also discussed.