Source-oriented health risk assessment of heavy metals in a soil-river continuum in northwest China  

作　　者：Enqi Yang Qingzheng Wang Zepeng Zhang Wenyan Shao Haiping Luo Xiong Xiao Fei Ni Jimin Mi Xiazhong Sun Qingyu Guan 

机构地区：[1]Gansu Key Laboratory for Environmental Pollution Prediction and Control,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China [2]College of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China

出　　处：《International Journal of Sediment Research》2024年第6期916-928,共13页国际泥沙研究(英文版)

基　　金：National Natural Science Foundation of China(Grant No.41671188);Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2022-28).

摘　　要：Heavy metals can easily accumulate in soil and river sediment due to their non-degradability,which seriously endangers the balance of the ecosystem and human health.Thus,research on heavy metals in soil-river composite ecosystems has great significance for risk mitigation.As a seasonal river in a semi-arid region(Yuzhong county)in northwest China,the Wanchuan River supports nearly 500,000 people,but has been polluted by the heavy metals from industrial wastes and sewage discharges.To protect precious water resources and soil ecosystems,it is urgent to do heavy metal research in the Wanchuan River basin.Towards this end,the current study collected samples of soil and river sedi-ment in this basin,and analyzed the distribution characteristics,health risks,and pollution sources of heavy metals,based on the pollution index evaluation method,health risk assessment,a geostatistical model,and the positive matrix factorization(PMF)model.The research results show that the contents of heavy metals in soil and river sediment were equivalent.However,contamination levels of heavy metals in stream sediment fell below that in soil.The results from the PMF model pointed out that natural sources contributed remarkably to the contents of heavy metals in soil,while industrial sources had the highest contribution to the contents of heavy metals in river sediment.According to the health risk assessment,among all selected metals,Cr brought about the highest carcinogenic risk,while As generated the highest non-carcinogenic risk.Source-oriented health risk assessment showed that natural sources(37%)and agricultural sources(50%),respectively,contributed most to the non-carcinogenic risks and carcinogenic risks induced by soil metals.Industrial sources contributed most both to the non-carcinogenic risks(46%)and carcinogenic risks(37%)induced by river sediment metals.The current research may offer theoretical bases for heavy metal pollution treatment in the soil-river continuum.

关 键 词：Heavy metals Soil-river continuum Pollution index evaluation Health risk assessment PMF model 

分 类 号：X52[环境科学与工程—环境工程]