Sulfate, nitrate and chloride in PM10 in the city of San José, Costa Rica: 2004-2006

the analysis of pm10 levels in two sites of the city of san josé (catedral metropolitana and junta de educación), in a period of 2.5 years (april 2004-october 2006), reported a median of 39 ± 8 and 27 ± 8 μg m-3, respectively. in addition, so42-, no3- and cl- levels were measured in both areas, where annual averages resulted not significantly different between each other. the analysis of main components, applied to the collected data, reveals a 65% of total variance explained by two factors. the pc1 correlates cl- concentration and wind speed, indicating a marine contribution to this ion. the pc2 shows a relation between so42-, no3- and pm10 levels, demonstrating its anthropogenic origin.