Characteristics of atmospheric dustfall fluxes and particle size in an open pit coal mining area and surrounding areas.

Atmospheric dustfall is solid air pollutant, which is mainly influenced by local sources, so it has a major impact on the local environment and the health of local residents. The objective of this study was to investigate the distribution characteristics of dustfall fluxes and particle size, and the meteorological factors affected them. Atmospheric dustfall was collected in an open-pit coal mining area and surrounding areas in the arid desert area of Northwest China from March to December 2018. Dustfall fluxes was measured, particle size was measured by using graphical methods and grain-size characteristic parameters, the meteorological factors were measured by using Spearman's Correlation Coefficient (SCC) and Stepwise Linear Regression (SLR), the correlations of dustfall fluxes, mean diameter, the content of particles at different grain-sizes were measured by using SCC. The results showed that dustfall fluxes were larger in open-pit mining area and desert area, and in spring and summer. The frequency of particle size distribution showed unimodal distribution, with the peak and the mean diameter in desert area being the largest, and being larger in spring and summer. The main meteorological factor affecting dustfall fluxes was wind speed and affecting particle size was relative humidity. There was no significant correlation between dustfall fluxes with mean diameter and the content of particles at different grain-sizes. The results of this study can provide areas and times where atmospheric dustfall control should be reinforced, and provide strong scientific support for regulatory policies.