Size Distribution of Chemical Components of Particulate Matter in Lhasa

To explore the contributions of chemical components in particulate matter Lhasa, size distribution characteristics components, such as carbonaceous species (organic carbon, OC; elemental EC), water-soluble ions (NH4+, Cl−, SO42−, and NO3−) trace elements (Na, Ca, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, K, Mg, Pb), were investigated from August 2018 to May 2019. Principal component analysis (PCA) was also used simulate source matter. The showed bimodal distributions, except for Cu. highest mass concentration OC appeared at < 0.49 μm, second one existed 1.5–3.0 μm winter or 3.0–7.2 other seasons. maximum concentrations NH4+, NO3− peaked 0.95–1.5 > 3.0 μm. For seasonality, SO42− considerably higher summer autumn; (except Ni), OC, EC presented values during late autumn winter. ratio between (4.15–33.80) indicated existence secondary pollution Lhasa. [NO3−]–[SO42−] ratios exceeding 1 suggested that currently predominant vehicle exhaust made a greater contribution aerosols. According results PCA, main sources Lhasa suspended dust, biomass burning, fossil fuel combustion, pollution, vehicular emissions.