ABSTRACT
Objective To know the contents of heavy metal (Pb,Cd,Cr,Ni,Cu,Zn,Hg and As) in home -grown vegetables in a city for providing evidences in vegetable planting.Methods A total of 248 samples from 5 vegetable plantation bases in four seasons were collected and the contents of heavy metal were determined and analyzed.Pb,Cd,Cr, Ni,Cu and Zn were determined by AAS,Hg and As were determined by AFS.The results were evaluated according to the national food sanitation standard limits.Results The exceeding rate of Ni in home -grown vegetables of root leaf and fruit was 48.48%,9.29% and 5.33% respectively,the exceeding rate of Cd was 12.12%,0.71 % and 8.00%,the exceeding rate of Pb was 0.00%,16.43% and 5.33%.The exceeding rate of other heavy metal were all below 5% or in line with the standard.The degree of heavy metal pollution decreased with season's order of autumn,summer,spring and winter.The content of As in leafy -vegetables was in significant association with the contents of AS in soil.Conclusion The heavy metal pollution of Ni,Pb and Cd in vegetables in the city is serious,and more attention should be paid to the heavy metal pollution.
ABSTRACT
Objective To know the status of heavy metal (Pb,Cd,Cr,Ni,Cu,Zn,Hg and As)contents and level of pollution in soils of vegetable plantation bases in Yongkang City.Methods A total of 84 samples from 5 vegetable plantation bases was collected and determined.Pb,Cd,Cr,Ni,Cu and Zn were determined by AAS.Hg and As were determined by AFS.And results were evaluated by using cumulative degree level,a single pollution index and Nemerow pollution index according to Safety Qualification of Agricultural Product -Environmental Requirements for Origin of Non -environmental Pollution Vegetable and Soil Environmental Quality Standard.Results The content of Cd was higher than the standard,while the other 7 heavy metals were in line with national standards.The Pb,Ni,Cu,As in vegetable plantation bases located on level one (fundamental change,clean),and Cd,Cr,Zn,Hg were level two (mild change, low accumulation).The integrated pollution index of vegetable plantation soils in Yongkang City was 0.86 (level two, warning limit).Conclusion The heavy metal contents in soils of vegetable plantation bases in Yongkang City are in line with national standards except Cd.