Substances in Urban Snow : A comparison of the contamination of snow in different parts of the city of Luleå, Sweden

Abstract

The aim of the study was to investigate how the quality of snow varies within a city. The study area is situated in the Lulea municipality, in northern Sweden (lat. 65°35′N and long. 22°10′E). For this study, the city was divided into three different types of areas: housing areas, city centre and outskirts. In one area of each type, sampling sites were selected. Snow samples were taken at nine occasions, once every fourteenth day in the city centre and in the housing area. Analyses were carried out for pH, conductivity, suspended solids and both the total and dissolved concentration of phosphorus and selected metals. It was concluded that traffic or activities related to traffic were a major source of heavy metals and phosphorus in urban snow, both in the city centre and in the housing area. Also, the type of area and the design of the street were important for the quality of snow. A clear relation was found between the pH and the quantity of suspended solids in the snow. Higher pH values were found in snow samples from sites with higher traffic loads, and lower pH values at sites, which were the no-traffic sites, with small quantities of particles. The particulate and dissolved substances in the snow behaved in different ways.