Seasonal variation of water-soluble inorganic ions in PM10 in a city of northwestern Turkey

The objective of this study was to determine the concentrations of inorganic ions present in particulate matter smaller than 10 mm (PM10), released into the environment by industrial, domestic and mobile sources in Duzce. To assess spatial variations, samples were collected from two sampling sites that had urban and suburban characteristics. Further, the process was carried out in two seasons to understand the seasonal variations. An ion chromatography device was used for analyzing the inorganic ion content in the collected samples. The highest levels of inorganic ion concentrations were measured at the urban sampling site during the winter campaign. Furthermore, the highest ion concentrations were measured for SO42- ion at both sampling sites and during both seasons, while the lowest concentrations were measured for Br-. Moreover, there were significant relationships between meteorological parameters and ion concentrations. A comparison of the cation and anion equivalence values using seasonal CE/AE (cation equivalence/anion equivalence) ratios showed that the aerosol matter had alkaline characteristics during both seasons. The mean value for the CE/AE ratios was 1.58 in winter and 2.06 in summer at the urban sampling site and 1.36 in winter and 1.52 in summer at the suburban sampling site. The interrelationships among the ions were determined by Pearson correlation analysis. Based on the correlation analyses, the ions emitted from common sources and those exposed to similar atmospheric conditions displayed strong correlations with each other.