ABSTRACT
The profound effects of man-made and natural particulate matter on health, environmental conditions, and climate cannot be understood without complete knowledge of the chemical and physical nature of such matter. The behavior of the particles is determined by the physical and chemical laws that are valid for finely divided matter. According to Fennelly, primary particulates are those injected directly into the atmosphere by chemical and/or physical processes. The solid airborne particles – varying widely in chemical composition, size, shape, as well as in homogeneity and concentration – are referred to as “dust,” regardless of their origin. The long-range transportation of airborne particles is the major concern, especially when high concentrations of dark particles are transmitted to Sweden from the European continent. During the dry and sunny weather of the summer months, small colorless particles containing different types of ammonium sulfates are responsible for white episodes.
