Ionic composition of PM10 in the area of Thessaloniki, Greece

Abstract Airborne particulate matter (PM 10 ) was collected from July 1997 to July 1998 at three locations in the city of Thessaloniki. PM 10 samples were analyzed for Cl − , NO 3 − , SO 4 2− , Ca 2+ , Mg 2+ , Na + , K + and NH 4 + . The average PM 10 concentrations were found similar in all three sites with higher values in cold period. The ionic content comprised the 17–23% of the PM 10 mass and sulfate made up the 35–38% of the PM 10 ionic content with an average concentration of 4.80–7.26 μg m −3 . Good correlation was found for SO 4 2− and NO 3 − with Ca 2+ , Mg 2+ and Cl − . Two factors were found to influence the variance of ionic constituents in PM 10 by using factor analysis. Data evaluation considering wind direction showed that higher PM 10 and other ionic concentrations are associated with calm conditions, suggesting influences of local sources.