Rare earth elements and health risk assessment of road dust from the vicinity of coal fired thermal power plants

Abstract

As emerging pollutants, rare earth elements (REEs) have been explored in different environmental samples. This is the first study to use road dust samples to monitor REEs form the vicinity of thermal power plant (TPPs). Road dust samples were collected from 17 locations (main and side roads) in a 15 km radius surrounding two coal-fired TPP (TPP Kostolac A & B, Serbia). Concentrations of nine REEs (Sc, La, Ce, Nd, Sm, Eu, Tb, Dy, Yb) were measured in the road dust samples (f < 63 μm, easily resuspended fraction size) using instrumental neutron activation analysis (INAA). We have found that the concentrations of REEs do not depend on the distance of the sampling location from TPP. There were no statistically significant differences between the main road and side road samples suggest that traffic is not the main source of REE in the studied area. Principal component analysis, hierarchical cluster analysis as well as geo-accumulation index (I_geo) and enrichment factors (EF) point to an enrichment with Dy of road dust samples collected in September. The road dust samples do not pose any harm to human health in the tested area, as shown by a hazard index of less than 0.1. Despite the low REE risk, it is important to consider the possibility of negative health consequences, mainly because these samples may contain numerous other organic and inorganic pollutants.