农业农村部环境保护科研监测所科研人员提出一种地质高背景区土壤镉安全阈值的估算方法
文章链接：
https://doi.org/10.1016/j.scitotenv.2023.162171
Highlights
•Cdcontentinvegetablespecieswasindecreasingorderofstemandbulb>leafy> solanaceous >beancultivars.
•Soilproperties(pH,SOM,andCEC)playamoreimportantroleinCdcontentinthevegetable.
•TheSSDcurvesindicatedsensitivityvariationsofCdin32vegetables.
•ThesoilCdthresholdwasclassifiedandvalidatedforthesafetyofvegetableproduction.
Abstract
Excessivedietaryintakeofcadmium(Cd)posestoxicityriskstohumanhealth,anditisthereforeessentialtoestablishaccurateandregionallyappropriatesoilCdthresholdsthatensurethesafetyofagriculturalproductsgrownindifferentareas.ThisstudyinvestigatedthedifferencesintheCdaccumulationin32vegetablevarietiesandfoundthattheCdcontentrangedfrom0.01to0.24mg·kg−1,anddecreasedintheorderofstemandbulbvegetables>leafyvegetables>solanaceouscrops>beancultivars.AcorrelationanalysisandstructuralequationmodelshowedthatpH,soilorganicmatter,andthecationexchangecapacityhadsignificanteffectsonCdaccumulationinthevegetablesandexplained72.1 %ofthevariance.Inaddition,speciessensitivitydistribution(SSD)curvesshowedthatstemandbulbvegetablesweremoresensitivetoCdthanothertypesofvegetables.UsingtheBurrTypeIIIfunctionforcurvefitting,wederivedCdthresholdsof6.66,4.15,and1.57mg·kg−1 forvegetablesoils.Thesethresholdswillensurethat20 %,50 %,and95 %ofthesevegetablevarietieswererisk–free,respectively.ThepredictedthresholdofsoilCdwasmorethantwicethatofChina'scurrentNationalSoilQualityStandard(GB15618–2018)forCdvalues.Therefore,soilscenariosandcultivarsshouldbeconsideredcomprehensivelywhendeterminingfarmlandsoilthresholds.ThepresentresultsprovideanewmodelforsettingsoilCdcriteriainhighgeologicalbackgroundareas.
食用Cd超标蔬菜是人体摄入Cd的来源之一，因此，建立地质高背景区土壤Cd安全阈值的估算方法对保障蔬菜安全生产和人体健康具有重要意义。该团队以云南省生菜、菠菜和辣椒等32个蔬菜品种的Cd毒理学数据和土壤pH、CEC和SOM等为研究对象，并基于Cd毒理学数据和关键土壤参数建立预测模型：Log10BCF =-0.807pH+0.401Log10SOM+0.011Log10CEC（R2=0.728,N=96, P <0.01）。利用BurrⅢ构建物种敏感性分布(SSD)曲线，得出的优先保护区、安全使用区和严格控制区土壤总Cd安全阈值分别为1.57、4.15 mg·kg−1和6.66 mg·kg−1。大田实验验证该阈值比我国现行土壤质量标准更准确、合理。
应用路径分析和物种敏感性分布法推导农田土壤Cd阈值