Abstract

In cities where industrial facilities, railways, and roads are interspersed, whether dust within the same environmental group has a similar elemental composition is a key question for defining monitoring units and selecting elements of interest. This study examined 12 elements at 16 sampling sites in Belgorod, Russia, using a local forest soil reference, hierarchical clustering, and Spearman rank correlation to analyze inter-site differences in multiple elements and their relationships with proximity to transport infrastructure. Cu and Zn exceeded the selected reference at all 16 sites, Pb exceeded the reference at 13 of the 14 sites with valid observations, and As exceeded the reference at only four sites. S12 had the highest concentrations of Zn, As, and Ba, whereas the correlations of Zn with As and Ba across sites were close to zero, indicating that local co-occurrence of high concentrations and overall covariation are not equivalent. Clustering identified a combination of relatively high Cu and As levels spanning thermal power plant, railway station, and industrial-traffic areas. The clustering results showed that multi-element similarity did not correspond one-to-one with the five environmental groups. Cu and As showed a relatively strong positive correlation (ρ=0.827, p<0.05), whereas railway distance was negatively correlated with Pb (ρ=-0.582, p<0.05). This study provides a basis for site selection and the choice of monitoring indicators for local environmental monitoring.

Keywords:Urban surface dust; Elemental composition; Hierarchical clustering; Spearman correlation