【摘要】 为探讨城郊污灌土壤-小麦体系中重金属Cu、Cd、Cr、Pb和Zn的迁移富集特征及潜在健康风险,选取北京城郊污灌区24块代表性小麦(Triticumaestivum)样地,运用高分辨电感耦合等离子体质谱仪(HR-ICP-MS)测定了土壤及小麦籽粒中消解态Cu、Cd、Cr、Pb和Zn含量。结果表明,污灌土壤中Cu、Cd、Cr、Pb和Zn的均值含量分别为26.51、0.24、101.29、28.04mg.kg-1和85.59mg.kg-1,高于北京土壤元素背景值,已出现积累现象;小麦籽粒中5种重金属含量顺序为Zn(52.38mg.kg-1)>Cu(6.09mg.kg-1)>C(r4.62mg.kg-1)>Pb(0.17mg.kg-1)>Cd(0.04mg.kg-1),其中Cr、Zn含量超出国家标准限值,食品安全需引起关注。在以污灌区小麦粉为主要食源条件下,健康风险评价显示:北京城郊污灌区单一重金属风险系数(HQ)尚未达到显著水平,但是郊区成人和儿童的5种重金属综合健康风险均大于1,4种不同人群的风险系数(HQ)和风险指数(HI)有相同的影响顺序,即郊区儿童>郊区成人>城区儿童>城区成人;5种重金属中,Cr所占风险比例最小,由Cu和Zn所引起的健康风险所占比例最高。表明对北京城郊污灌区小麦籽粒主要消费区域和流通渠道以及由此引发的居民(尤其郊区儿童和成人)重金属健康风险需要予以关注,预防食品安全危害的发生。更多还原

【Abstract】 Heavy metals(HMs) may cause deleterious effects on human health due to the ingestion of food grain grown in contaminated soils.Heavy metal contaminated soils resulting from sewage and wastewater irrigation is the major concern because the potential risk on human health was involved.In the present study,in order to acquire better understanding of the characteristics of translocation and enrichment of heavy metal in sewage irrigated soil-wheat(Triticum aestivum) system,we collected the samples from 24 sewage-irrigated fields located at the suburb Beijing.The concentrations of Cu,Cd,Cr,Pb and Zn in the soil and wheat seed were determined by High Resolution Inductively Coupled Plasma Mass Spectrometry(HR-ICP-MS).Based on the results,we assessed the potential health risk for local residents.The results indicated that the average concentration of Cu,Cd,Cr,Pb and Zn in the sewage-irrigated soil was 26.51,0.24,101.29,28.04 mg·kg-1 and 85.59 mg·kg-1 respectively,which were higher than soil background value of Beijing,revealing the heavy metal accumulation in the soils of sewage-irrigated fields.Concentration or accumulation of Cu,Cd,Cr,Pb and Zn in wheat seed followed the sequence:Zn(52.38 mg·kg-1)>Cu(6.09 mg·kg-1)>Cr(4.62 mg·kg-1)>Pb(0.17 mg·kg-1)>Cd(0.04 mg·kg-1).The Zn and Cr concentrations of several wheat seed samples exceeded the permissible limits of China standard for food safety.The facts emphasize that we should be pay additional attention on food safety.In relation to non-carcinogenic risks,Hazard Quotient(HQ) of individual metal presented values inside the safe interval.However,health risk due to the added effects of five HMs was significant for rural children and rural adults,but not for urban adults and urban children.HQ(individual risk) and HI(Hazard Index of aggregate risk) to different inhabitants due to HMs followed the same sequence:country children>country adults>urban children>urban adults.Amongst the HMs,potential health hazards due to Cu and Zn were large,and that due to Cr was the minimum.It suggests we should pay more attention on its circulation area and scope of wheat grain in sewage-irrigated area and the potential added threat of HMs to the health of country inhabitants(both children and adults) through consumption of wheat in Sewage-irrigated area of Beijing.更多还原