Changes in sulphur dioxide concentrations in the atmospheric air assessed during short-term measurements in the vicinity of Olsztyn, Poland

Abstract

Sulphur dioxide is one of the principal gases responsible for the quality of atmospheric air. Air pollution, even relatively low one, is not indifferent to human health. In 2007-2009, an investigation was carried out to follow changes in the concentration of sulphur dioxide in atmospheric air, in different time intervals, depending on the air temperature and humidity. This paper draws on results of continuous measurements taken at the Station of Monitoring the Immission of Air Pollutants in Olsztyn-Kortowo. The measured concentrations of SO 2 were presented graphically as means for different time intervals. It has been demonstrated that changes in SO 2 concentrations were mainly induced by drops in temperatures, emissions and other industrial actitivities, as well as the course of the growth and development of plants. The highest concentrations appeared at noon and the lowest ones were at night. Analysis of similarities verified hourly variations in the SO 2 concentrations in air. Four distinc groups were distinguished: nocturnal (1:00-7:00 a.m.), mid-day (10:00 a.m.-3:00 p.m.), a group with two time intervals (8:009:00 a.m.; 4:00-7:00 p.m.) and late evening (8:00 p.m. - midnight). Considering the aerial concentration levels of this gas in monthly intervals, high similarity was observed between the early spring versus the autumn and winter seasons. Dependences between SO 2 concentrations and temperature were confirmed by analysis of the correlation coefficients and linear regression equations. Likewise, relationships between SO 2 concentrations and air humidity were analyzed in different time intervals and presented both graphically and statistically, by computing correlations and regression equations. Irrespective of the source of emission and meteorological con