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, ...