不同砷水平下小麦砷迁移累积特征及健康风险评价  

Characteristics of Arsenic Migration and Accumulation in Wheats under Different Arsenic Levels and Its Health Risk Assessment

作　　者：焦位雄 杨虎德[1] 林大松 李崇霄 冯丹妮 JIAO Weixiong;YANG Hude;LIN Dasong;LI Chongxiao;FENG Danni(Institute of Soil,Fertilizer and Water-saving Agriculture,Gansu Academy of Agricultural Sciences,Lanzhou Gansu 730070,China;Environmental Protection Research and Monitoring Institute,Ministry of Agriculture and Rural Affairs,Tianjin 300191,China;Gansu Provincial Agricultural Ecology and Resource Protection Technology Extension Station,Lanzhou Gansu 730000,China)

机构地区：[1]甘肃省农业科学院土壤肥料与节水农业研究所,甘肃兰州730070 [2]农业农村部环境保护科研监测所,天津300191 [3]甘肃省农业生态与资源保护技术推广总站,甘肃兰州730000

出　　处：《寒旱农业科学》2024年第5期445-450,共6页Journal of Cold-Arid Agricultural Sciences

基　　金：甘肃省科技重点研发计划(18YF1FA094);甘肃省农业科学院中青年/博士基金(2022GAAS56)。

摘　　要：通过研究土壤在不同浓度As污染条件下的小麦生长发育及As迁移富集特征,以评估不同As浓度胁迫下小麦籽粒的健康风险,进而提出适宜甘肃省小麦生产实际的土壤As污染临界值。以灌淤土为研究对象,以春小麦品种宁春4号为指示作物,参照《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)中土壤As风险筛选值,按照土壤质量标准0~3倍As含量设置7个浓度梯度,进行了土壤-小麦系统As毒性盆栽试验。结果显示,不同浓度As胁迫下,小麦根系、茎叶、籽粒中As含量均随土壤As浓度的增加而增加,小麦植株不同部位的As含量由高到低的顺序为根系、茎叶、籽粒。小麦不同部位对As的富集能力表现为:根系>茎叶>籽粒,且根系、茎叶As富集能力随着土壤中As浓度的增加大体呈先增加后减小的趋势。As在小麦植株中转运系数表现为TF茎叶/根>TF籽粒/茎叶>TF籽粒/根,以根系向茎叶迁移过程为主。以甘肃省成人为评价对象,利用人体健康风险评价模型,采用靶标危害系数法(THQ)得出,除对照不添加As2O5处理外,其余As胁迫各处理的小麦籽粒人体健康风险系数均超出USEPA推荐的最大可接受风险临界值(即THQ>1.00),且随土壤As含量增加呈先升高后降低的趋势。根据甘肃省当地居民饮食习惯,结合人体健康风险评价模型,认为甘肃省小麦安全生产土壤推荐As浓度应低于29.200 mg/kg。This study explored the growth,development,and arsenic(As)migration and accumulation characteristics of wheat in soils with different As concentrations to assess the health risks associated with wheat grains under varying levels of As stress and to propose a critical value for soil As contamination that is practical for wheat production in Gansu Province.Using anthropogenic-alluvial soil and Ningchun 4 variety of spring wheat as indicators,and referencing the soil As risk screening values from the'Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land(Trial)'(GB 15618—2018),7 concentration gradients were set from 0 to 3 times the soil quality standard As content for a soil-wheat system toxicity pot experiment.The results showed that As content in the roots,stems,and grains of wheat increased with soil As concentration,with the highest to lowest As content in the plant parts being roots,stems,and grains,respectively.The ability of different wheat parts to accumulate As was in the order:roots>stems>grains,with the accumulation capacity in roots and stems initially increasing and then decreasing with soil As concentration.The transfer coefficients(TF)for As in wheat plants were highest from roots to stems(TF stems/roots)followed by grains to stems(TF grains/stems)and grains to roots(TF grains/roots).Using adults in Gansu Province as the assessment subject and employing a human health risk assessment model with the Target Hazard Quotient(THQ)method,it was found that except for the control without added As2O5,the THQ values for all other As-stressed treatments exceeded the USEPA's recommended maximum acceptable risk threshold(THQ>1.00),with a trend of initially increasing and then decreasing with rising soil As content.Based on local dietary habits and the human health risk assessment model,it is recommended that the safe production soil As concentration for wheat in Gansu Province should be less than 29.200 mg/kg.

关 键 词：春小麦 As 胁迫 浓度 灌淤土 富集迁移 THQ法 人体健康风险评价 

分 类 号：S512.1[农业科学—作物学] X53[环境科学与工程—环境工程]