A study on the heavy metal pollution of home -grown vegetables in a city / 预防医学

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.