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| Distribution characteristics of heavy metals in Tibetan Plateau surface soils and its influencing factors |
| LIU Xiao-li1,2, Gao Wen-hua1, Wei Ting3, Dong Zhi-wen2, Shao Ya-ping4 |
1. College of Geography and Environmental Science, National Demonstration Center for Experimental Environment and Planning Education, Henan University, Kaifeng 475004, China;
2. School of Geography and Information Engineering, China University of Geosciences, Wuhan 430078, China;
3. State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
4. Institute of Geophysics and Meteorology, University of Cologne, Germany |
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Abstract Due to the delicate ecological balance of the Tibetan Plateau (TP) and its heightened vulnerability to human-induced impacts, there has been a growing scholarly focus on investigating heavy metal pollution in the plateau's environment in recent years. In this study, we conducted a comprehensive analysis of nine distinct heavy metal elements (HMs), including As, Cr, Co, Ni, Cu, Mo, Cd, Pb, and Sb, using topsoil samples collected from the TP during the period of 2021~2022. This analysis was complemented by evaluating snow and cryoconite samples obtained during the same timeframe. Our investigation revealed a significant disparity in HM content between TP topsoil (with an average of 256.5μg/g) and snow-cryoconite samples (with an average of 14.6μg/L). Specifically, the calculated average Igeo value for As indicated moderate pollution (1.32), while the remaining heavy metals in the soils showed predominantly non-polluted to lightly polluted levels. Clear differences in both composition and spatial distribution of HMs were evident between the topsoil and the snow-cryoconite matrix. Regarding spatial distribution, composition, and Enrichment Factors (EFs), congruence was observed among different regions in the topsoil samples. Through a triangulation of correlation analysis, principal component analysis, and the APCS-MLR method, our investigation identified three principal sources of HMs in the topsoil: coal combustion (42.3%), inherent natural sources within the surface soil (20.6%), and vehicular emissions (14.2%). Disparities in the composition and distribution of HMs within high-altitude glaciers and topsoil samples were attributed to local processes of natural weathering and anthropogenic influences on the topsoil. These factors tend to mask the influence of long-range transport (LRT) on HM content in topsoil. Conversely, HMs present in snow and cryoconite samples are more susceptible to the effects of LRT sources. This study provides a holistic overview of the composition of HMs in the extensive expanse of TP topsoil,highlighting significant enrichment of certain elements, such as As, while emphasizing an overall condition of relative purity in terms of HM content.
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Received: 28 September 2023
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[1] An S, Liu N, Li X, et al. Understanding heavy metal accumulation in roadside soils along major roads in the Tibet Plateau[J]. Science of The Total Environment, 2022,802:149865.
[2] Chen P, Kang S, Bai J, et al. Yak dung combustion aerosols in the Tibetan Plateau:Chemical characteristics and influence on the local atmospheric environment[J]. Atmospheric Research, 2015,156:58-66.
[3] Qiao D, Wang G, Li X, et al. Pollution, sources and environmental risk assessment of heavy metals in the surface AMD water, sediments and surface soils around unexploited Rona Cu deposit, Tibet, China[J]. Chemosphere, 2020,248:125988.
[4] Zhang B, Jia T, Peng S, et al. Spatial distribution, source identification, and risk assessment of heavy metals in the cultivated soil of the Qinghai-Tibet Plateau region:Case study on Huzhu County[J]. Global Ecology and Conservation, 2022,35:e02073.
[5] Li C, Kang S, Zhang Q. Elemental composition of Tibetan Plateau top soils and its effect on evaluating atmospheric pollution transport[J]. Environmental pollution, 2009,157(8/9):2261-2265.
[6] Dong Z, Kang S, Qin X, et al. New insights into trace elements deposition in the snow packs at remote alpine glaciers in the northern Tibetan Plateau, China[J]. Science of The Total Environment, 2015, 529:101-113.
[7] Jiao X, Dong Z, Kang S, et al. New insights into heavy metal elements deposition in the snowpacks of mountain glaciers in the eastern Tibetan Plateau[J]. Ecotoxicology and Environmental Safety, 2021, 207:111228.
[8] Wei T, Dong Z, Kang S, et al. Atmospheric deposition and contamination of trace elements in snowpacks of mountain glaciers in the northeastern Tibetan Plateau[J]. Science of the Total Environment, 2019,689:754-764.
[9] Wu R, Dong Z, Cheng X, et al. Heavy metal levels and sources in suspended particulate matters of the glacier watersheds in Northeast Tibetan Plateau[J]. Frontiers in Environmental Science, 2022:1140.
[10] 王昱,朱家乐,冯起,等.黑河上中游流域梯级库区夏季重金属汇源解析[J]. 中国环境科学, 2023,43(4):1895-1905. Wang Y, Zhu J L, Feng Q, et al. Distribution charateristics and aggregating releasing of heavy metals during Summer in a cascade Reservoir of upper and middle reaches of the Heihe River[J]. China Environmental Science, 2023,43(4):1895-1905.
[11] 杨安,邢文聪,王小霞,等.西藏中部河流、湖泊表层沉积物及其周边土壤重金属来源解析及风险评价[J]. 中国环境科学, 2020,40(10):4557-4567. Yang A, Xing W C, Wang X X, et al. Source and risk assessment of heavy metals in surface sediments of rivers, lake and their surrounding soils in central Tibet[J]. China Environmental Science, 2020,40(10):4557-4567.
[12] Sheng J, Wang X, Gong P, et al. Heavy metals of the Tibetan top soils:level, source, spatial distribution, temporal variation and risk assessment[J]. Environmental Science and Pollution Research, 2012, 19:3362-3370.
[13] 杨安,王艺涵,胡健,等.青藏高原表土重金属污染评价与来源解析[J]. 环境科学, 2020,41(2):886-894. Yang A, Wang Y H, Hu J, et al. Evaluation and source of heavy metal pollution in surface soil of Qinghai-Tibet Plateau[J]. China Environmental Science, 2020,41(2):886-894.
[14] 杜昊霖,王莺,王劲松,等.青藏高原典型流域土壤重金属分布特征及其生态风险评价[J]. 环境科学, 2021,42(9):4422-4431. Du H L, Wang Y, Wang J S, et al. Distribution charateristics and ecological risk assessment of soil heavy metals in typical watersheds of Qinghai-Tibet Plateau[J]. China Environmental Science, 2021, 42(9):4422-4431.
[15] Wu J, Lu J, Li L, et al. Pollution, ecological-health risks, and sources of heavy metals in soil of the northeastern Qinghai-Tibet Plateau[J]. Chemosphere, 2018,201:234-242.
[16] Guan Z H, Li X G, Wang L. Heavy metal enrichment in roadside soils in the eastern Tibetan Plateau. Environ. Sci. Pollut. Res. Int. 2018,25:7625-7637.
[17] Wang G, Zeng C, Zhang F, et al. 2017a. Traffic-related trace elements in soils along six highway segments on the tibetan plateau:influence factors and spatial variation. Sci. Total Environ. 581-582,811-821.
[18] Bing H, Wu Y, Zhou J, et al. Mobility and eco-risk of trace metals in soils at the Hailuogou Glacier foreland in eastern Tibetan Plateau[J]. Environmental Science and Pollution Research, 2016,23:5721-5732.
[19] Lee K, Do Hur S, Hou S, et al. Atmospheric pollution for trace elements in the remote high-altitude atmosphere in central Asia as recorded in snow from Mt. Qomolangma (Everest) of the Himalayas[J]. Science of the Total Environment, 2008,404(1):171-181.
[20] Liu H L, Zhou J, Li M, et al. Study of the bioavailability of heavy metals from atmospheric deposition on the soil-pakchoi (Brassica chinensis L.) system[J]. Journal of hazardous materials, 2019,362:9-16.
[21] Feng W, Guo Z, Xiao X, et al. Atmospheric deposition as a source of cadmium and lead to soil-rice system and associated risk assessment[J]. Ecotoxicology and Environmental Safety, 2019,180:160-167.
[22] Wilding L P. Spatial variability:Its documentation, accommodation and implication to soil survey[M]. Spacial Variations, 1985.
[23] Wang X, Cheng G, Zhong X, et al. Trace elements in sub-alpine forest soils on the eastern edge of the Tibetan Plateau, China[J]. Environmental Geology, 2009,58:635-643.
[24] 张照伟,李文渊,王亚磊,等.南祁连化隆地区镁铁-超镁铁质侵入岩地质、地球化学特征与铜镍成矿[J]. 地质学报, 2015,89(3):632-644. Zhang Z W, Li W Y, Wang Y L, et al. Geological and geochemical charateristics of Mafic-ultramafic intrusions in the Hualong Area, Southern Qilian Mountains and its Ni-Cu mineralization[J]. Acta Geologica Sinica, 2015,89(3):632-644.
[25] Huang J, Wu G, Gu F, et al. Elemental composition of the topsoil fine fraction at and around the Tibetan plateau[J]. Environmental Pollution, 2023,121098.
[26] Al-Momani I F. Trace elements in atmospheric precipitation at Northern Jordan measured by ICP-MS:acidity and possible sources[J]. Atmospheric Environment, 2003,37(32):4507-4515.
[27] Hassan S K M. Metal concentrations and distribution in the household, stairs and entryway dust of some Egyptian homes[J]. Atmospheric Environment, 2012,54:207-215.
[28] Lu X, Wang L, Li L Y, et al. Multivariate statistical analysis of heavy metals in street dust of Baoji, NW China[J]. Journal of hazardous materials, 2010,173(1-3):744-749.
[29] Nriagu J O, Pacyna J M. Quantitative assessment of worldwide contamination of air, water and soils by trace metals[J]. Nature, 1988,333(6169):134-139.
[30] Yuen J Q, Olin P H, Lim H S, et al. Accumulation of potentially toxic elements in road deposited sediments in residential and light industrial neighborhoods of Singapore[J]. Journal of environmental management, 2012,101:151-163.
[31] Liu Y, Hou S, Hong S, et al. Atmospheric pollution indicated by trace elements in snow from the northern slope of Cho Oyu range, Himalayas[J]. Environmental earth sciences, 2011,63:311-320.
[32] An S, Liu N, Li X, et al. Understanding heavy metal accumulation in roadside soils along major roads in the Tibet Plateau[J]. Science of The Total Environment, 2022,802:149865.
[33] 李萍.金华市耕地土壤重金属污染空间特征、来源解析及健康风险评价[D]. 金华:浙江师范大学, 2023.DOI:10.27464/d.cnki.gzsfu. 2022.000561. Li P. Spatial distribution, source analysis and health risk assessment of heavy metal pollution in cultivated land in Jinhua City[D]. Jinhua:Zhejiang Normal University, 2023.DOI:10.27464/d.cnki. gzsfu.2022.000561.
[34] Li Y, Li Z, Cozzi G, et al. Signals of pollution revealed by trace elements in recent snow from mountain glaciers at the Qinghai-Tibetan plateau[J]. Chemosphere, 2018,200:523-531.
[35] Cong Z, Kang S, Liu X, et al. Elemental composition of aerosol in the Nam Co region, Tibetan Plateau, during summer monsoon season[J]. Atmospheric Environment, 2007,41(6):1180-1187.
[36] Cong Z, Kawamura K, Kang S, et al. Penetration of biomass-burning emissions from South Asia through the Himalayas:new insights from atmospheric organic acids[J]. Scientific reports, 2015,5(1):1-7,33.
[37] 刘亚军,张玉兰,康世昌,等.青藏高原东南部冰川雪冰重金属元素特征[J]. 冰川冻土, 2017,39(6):1200-1211. Liu Y J, Zhang Y L, Kang S C, et al. Charateristics of heavy matal elements deposited on glaciers in the southeastern Tibetan Plateau[J]. Journal of Glaciology and Geocryology, 2017,39(6):1200-1211. |
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