Elemental composition of aerosols collected in the glacier area on Nyainqêntanglha Range, Tibetan Plateau, during summer monsoon season

In order to investigate the elemental composition in atmospheric aerosols and its sources in the glacier area over the Tibetan Plateau (TP), seven totally suspended particle samples were collected continuously at the col of the Zhadang glacier (30°28′N,90°39′E,5800 m a.s.l.), Nyainqêntanglha Range, southern TP, from June to October 2006. Twenty-seven elements (Li, Be, B, Na, Mg, Al, K, Ca, Sc, Ti, V, Fe, Mn, Zn, Ga, As, Rb, Sr, Y, Cd, Cs, Ba, Tl, Pb, Bi, Th, U) were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The result indicates that the concentrations of most elements (especially crustal elements) are lower than values at the Nam Co Station during the same period of 2005, and also much lower than other sites in the TP such as Wudaoliang and Waliguan. This suggests that elemental compositions of aerosols in the Zhadang glacier area may represent the background levels of the middle/upper troposphere over the TP. Crustal enrichment factors (EFs) reveal that several elements (e.g. B, Zn, As, Cd, Pb and Bi) may have anthropogenic sources. The southern TP is mainly influenced by the summer Indian monsoon during the sampling period. Backward air mass trajectory analysis suggests that air masses in the region may originate from South Asia. Therefore, anthropogenic pollutants from South Asia may be transported by the summer Indian monsoon to the region which clearly affects the atmospheric environment in the southern TP during the summer monsoon season.