Mass concentration and composition of TSP in Kashgar, Xinjiang, China

Abstract

Total suspended particulate matter (TSP) and dust fall concentrations in the ambient air of Kashgar, Xinjiang, were measured in a field campaign. The results revealed that the high levels of TSP and dust fall among literature were reported in data. TSP and dust fall showed the similar monthly variations. Monthly TSP level in air ranged between 304.0 and 2030.6 μg/m3, and dust fall loadings varied from 8.6 to 248.1 g/m2 during the field campaign. Wind speed and direction were identified to be the most important meteorological factor affecting the concentrations of TSP. Central Asia and the Tarim Basin were identified to be the two major source regions from where TSP and dust were transported to Kashgar by both westerly and easterly winds. The dominant anion in TSP was SO4 2−, followed by Cl−, NO3 −, and F−. The dominant cation in sampled TSP was Ca2+, followed by Na+, K+, NH4+, and Mg2+. The principle component analysis showed that the first principal component (PC1) of the ion in TSP samples from the Kashgar region accounted for 44.81 % of total data variance, and the second principal component (PC2) accounted for 18.65 %. Mg2+, Na+, K+, Ca2+, NO3 −, SO4 2−, and Cl− have greater loadings in the PC1, and Cl− and NH4 + have greater loadings in the PC2. This study suggests that desert dust, earth crust, soil, and anthropogenic activities such as fossil fuel combustion were the main sources of TSP in the Kashgar area.