Spatial distribution and risk assessments of mercury in topsoils of Central Asia  

作　　者：Zhengzheng Yang Junming Guo Shiwei Sun Dingming Ni Pengfei Chen Dipesh Rupakheti Huhu Kang Sabur F Abdullaev Salamat Abdyzhapar uulu Shichang Kang 

机构地区：[1]Key Laboratory of Western China's Environmental Systems(Ministry of Education),College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China [2]State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [3]Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China [4]University of Chinese Academy of Sciences,Beijing 100049,China [5]Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Collaborative Innovation Center of Atmospheric Environment and Equipment Technology,School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China [6]S.U.Umarov Physical Technical Institute of the National Academy of Sciences of Tajikistan,Dushanbe 734063,Tajikistan [7]Research Center for Ecology and Environment of Central Asia(Bishkek),720001,Kyrgyzstan [8]Geography Department,Geology Institute,National Academy of Sciences,720001,Kyrgyzstan

出　　处：《Geoscience Frontiers》2023年第4期270-279,共10页地学前缘（英文版）

基　　金：This study was supported by Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(XDA20040501);State Key Labora-tory of Cryospheric Science,Chinese Academy of Sciences(Grant No.SKLCS-ZZ-2022);China Postdoctoral Science Foundation(2021M693375);the Startup Foundation for Introducing Talent of NUIST(2022r024).

摘　　要：Central Asia is one of the largest arid areas on earth,yet little is known about the concentration levels and risks of mercury(Hg)in the soils of this region.In this study,extensive sampling of topsoils(0-10 cm)from representative landscapes was carried out over Central Asia(i.e.,Tajikistan,Uzbekistan,and Kyrgyzstan).The total mercury(THg)concentrations in topsoils varied widely from 1.6 to 908.0 ng/g,with high values observed in samples collected in the capital cities and urban areas.Topsoil THg concentrations among different landscapes showed a decreasing order of urban(79.8±184.0 ng/g)>woodland(27.3±28.9 ng/g)>grassland(20.6±15.9 ng/g)>farmland(18.3±9.5 ng/g)>desert(12.3±8.0 ng/g).High THg concentrations were found in the capital cities/urban clusters,followed by a gradual decrease towards the peripheries.THg concentrations were found to be negatively correlated with the distance from the sampling sites to their nearest cities,indicating that anthropogenic emissions significantly influenced the spatial distribution of topsoil Hg.A significant correlation between THg concentrations and topsoil total organic carbon(TOC)contents was also observed,suggesting that TOC played an essential role in the spatial distribution of topsoil Hg.The assessments of pollution and potential ecological risk suggested that topsoils in highly densely-populated areas were contaminated by Hg and had higher degrees of potential ecological risks.The health risk assessment results showed that the exposure risk of topsoil Hg to children was higher than that to adults.Fortunately,there was no unacceptable human health risk of topsoil Hg.This study clarified the spatial distribution and risks of Hg in the Central Asian topsoils,offering new insight into the risk prevention and control of soil Hg.

关 键 词：MERCURY TOPSOIL LANDSCAPE Spatial distribution Risk assessment Central Asia 

分 类 号：X820.4[环境科学与工程—环境工程] TU991.21[建筑科学—市政工程]