Spatial and Temporal Variations of Major Acidic Species in Pm2.5 Particle Fraction in Zagreb Air

This paper presents the spatial and temporal mass concentration variations of major acidic species (chlorides, nitrates and sulphates) in high risk particle fraction PM2..5 in Zagreb air. The sampling was carried out at four measuring sites during the summer of 2002 (June – July) and winter 2002-2003 (November – January). The results show no significant differences in pollutant concentration levels between the measuring sites in the winter, while significant differences were found for nitrates and sulphates in the summer. Higher mass concentrations of all pollutants were measured in the winter. The mass concentrations of investigated anions showed significant seasonal differences, except for chlorides at two sampling sites. The most abundant species contributing to the PM2.5 mass were: sulphates > nitrates > chlorides.