Influence of long-range transboundary transport on atmospheric water vapor mercury collected at the largest city of Tibet.
Monsoon circulation is an important process that affects long-range transboundary transport of anthropogenic contaminants such as mercury (Hg). During the Indian monsoon season of 2013, a total of 92 and 26 atmospheric water vapor samples were collected at Lhasa, the largest city of the Tibet, for Hg and major ions analysis, respectively. The relatively low pH/high electronic conductivity values, together with the fact that NH4(+) in atmospheric water vapor was even higher than that determined in precipitation of Lhasa, indicated the effects of anthropogenic perturbations through long-range transboundary atmospheric transport. Concentrations of Hg in atmospheric water vapor ranged from 2.5 to 73.7ngL(-1), with an average of 12.5ngL(-1). The elevated Hg and major ions concentrations, and electronic conductivity values were generally associated with weak acidic samples, and Hg mainly loaded with anthropogenic ions such as NH4(+). The results of principal component analysis and trajectory analysis suggested that anthropogenic emissions from the Indian subcontinent may have largely contributed to the determined Hg in atmospheric water vapor. Furthermore, our study reconfirmed that below-cloud scavenging contribution was significant for precipitation Hg in Lhasa, and evaluated that on average 74.1% of the Hg in precipitation could be accounted for by below-cloud scavenging.
Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China; Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, Mikkeli FI 50130, Finland.
Jie
J
Huang
State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: shichang.kang@lzb.ac.cn.
Shichang
S
Kang
Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China.
Lide
L
Tian
Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; Graduate University of the Chinese Academy of Sciences, Beijing 100049, China.
Junming
J
Guo
Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China.
Qianggong
Q
Zhang
Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China.
Zhiyuan
Z
Cong
Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, Mikkeli FI 50130, Finland.
Mika
M
Sillanpää
State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; Graduate University of the Chinese Academy of Sciences, Beijing 100049, China.
Shiwei
S
Sun
State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
Lekhendra
L
Tripathee
D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring; D005740:Gases / Q000032:analysis*; D008628:Mercury / Q000032:analysis*; D013227:Steam / Q000032:analysis*; D018609:Tibet
D000393:Air Pollutants; D005740:Gases; D013227:Steam; D008628:Mercury
Atmospheric water vapor; Long-range transboundary atmospheric transport; Mercury; Monsoon circulation; Tibetan Plateau