Spatial distribution of heavy metals in the topsoil on roundabouts in Zielona Góra, Poland

In most cases, traffic pollution deposition is linear with regularities in its distribution in transect routes (canyon-type effect). The aim of this study is to identify different characteristics of heavy metal deposition on large roundabouts, which are open spaces atypical in terms of the characteristics of the air mass flow along road lanes. The study was conducted on four large roundabouts in Zielona Góra. The content of the selected elements in the tested soils was: Cd 0.54–1.22 mg·kg⁻¹ d.m., Cu 3.60–29.3 mg·kg⁻¹ d.m., Cr 2.17–4.63 mg·kg⁻¹ d.m., Zn 26.6–89.9 mg·kg⁻¹ d.m., Pb 10.9–75.4 mg·kg⁻¹ d.m. The geo-accumulation index was also calculated. The threshold values for communication areas were not exceeded, and the content of the elements was generally comparable between the roundabouts. However, we found some differences within particular roundabouts.