Impact of traffic-related emissions on air quality assessed via moss bags technique.

The impact of traffic-related potentially toxic element emissions on air contamination was evaluated. The moss bags were exposed on three highways (Leningradskoye, Yaroslavskoye, and Dmitrovkoye) in Central Russia. The combined use of Inductively Coupled Plasma Optical Emission Spectroscopy and direct mercury analyzer allowed the determination of Al, Ba, Co, Cd, Cr, Cu, Fe, Mn, Ni, P, Pb, Sr, S, V, Zn, and Hg in both exposed and unexposed moss samples. Besides P, the content of elements in exposed moss samples was comparable to or exceeded the values obtained for unexposed samples. The most pronounced uptake of elements was marked for the Leningradskoye highway, followed by Yaroslavskoye and Dmitrovkoye highways. Relative accumulation and enrichment factors have enabled us to assess the level of moss enrichment and to identify elements with a major influence on air pollution. Principle component analysis highlighted two groups of elements with common sources of provenance mainly related to the Leningradskoye highway. The relationships between elements content and distance from the road edge were investigated. The results of the principal component analysis indicate that the distance from the road is affecting the distribution of some potentially toxic elements, in particular, Al, Cu, Co, Cr, Fe, Ni, and V.