Impact of noise barriers on the dispersal of solid pollutants from car emissions and their deposition in soil

Abstract

Abstract Despite the existence of various methods aimed at protecting the environment from the negative influence of roads, there is a lack of adequate techniques for monitoring and reducing the spread of roadside pollution into the air and soils. The aim of this study was to assess the impact of noise barriers (sound walls) on the dispersal and soil deposition of solid pollutants from car emissions, based on both quantitative and qualitative analysis. Magnetic susceptibility measurements, trace elements analyses, and platinum (Pt) and rhodium (Rh) content determinations were performed on soil samples collected in the vicinity of various types of noise barrier. Previous investigations have shown that most traffic emissions are deposited in the close vicinity of roads (up to 10 m), with pollution levels decreasing with increasing distance from the road edge. However, the results of the present study indicate that this distribution is disturbed in areas in which noise barriers are located. Moreover, additional soil enrichment with trace elements was observed at approx. 10-15 m behind the barriers. The spatial distribution of trace elements contents in the tested soil samples corresponded to the magnetic susceptibility values. High Fe, Zn, Mn and Pb levels were observed adjacent to noise barriers composed of sawdust concrete and steel panels.