Size distribution of elemental components in atmospheric particulates from a typical industrial and mining city of Central China

As one of crucial factor in atmospheric particulate matter, elemental components exhibit distinct distribution features within different particle size ranges. Crustal elements (such as Al, Si, Fe, Ca, Mg) are primarily concentrated in coarse particulate matter, whereas elements originating from anthropogenic pollution sources (such as heavy metal elements including Pb, Zn, Cd, As, Cr) are more frequently distributed in fine particulate matter. Furthermore, some specific elements may also exhibit peak concentrations in particular particle size, which is closely related to their sources and formation processes. In recent years, there are still some challenges and deficiencies. Further research is needed on the particle size distribution characteristics of complex pollution sources (such as industrial emissions and traffic emissions). Additionally, there is a need to enhance the understanding of the transformation mechanisms and health effects of elemental components within particulate matter. This study selected a typical industrial and mining city to investigate particle size distribution characteristics of elemental components in atmospheric particulate matter. Anderson Eight-Stage Particulate Impactor Sampler was used to collect atmospheric particulate matter in the urban area of Huangshi during winter and summer. Nine particle size range samples were obtained spanning from 0 to 0.4 µm, 0.4 to 0.7 µm, 0.7 to 1.1 µm, 1.1 to 2.1 µm, 2.1 to 3.3 µm, 3.3 to 4.7 µm, 4.7 to 5.8 µm, 5.8 to 9.0 µm, and 9.0 to 10 µm. Energy Dispersive X-Ray Fluorescence Spectrometry (ED-XRF) was employed to determine the concentrations of 17 elemental components, including S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sb, Ba, and Pb. Elements Ca, S, Fe, K, Zn, Ba, and Pb were identified as the primary pollutants during the sampling period. All the elemental concentrations exhibited distinct seasonal variations, demonstrating higher levels in winter compared to summer. Each element demonstrated distinct particle size distribution characteristics with peak concentrations for most elements occurring in the 5.8 to 9.0 µm range and peaks for the remaining elements in the 0.4 to 1.1 µm range. The highest elemental concentrations in both summer and winter were mainly distributed in the 5.8 to 9.0 µm and 0.7 to 1.1 µm size ranges. In summer, most elemental concentrations were negatively correlated with relative humidity. However, in winter, there was no significant correlation with relative humidity. Rainfall had a certain scavenging effect on elements but was also influenced by other meteorological factors. Element S had the highest enrichment factor values in both summer and winter. Element Cl was highly enriched in finer particle size fractions in both seasons. Most elements were slightly enriched across all particle size fractions. Principal component analysis further identified the main sources as soil dust and wind-blown sand, coal combustion, vehicle exhaust emissions, biomass burning, mining and construction activities, and other pollution sources. These findings contribute to the formulation of effective pollution control measures and the protection of public health.