Studies On Concentrations Of Heavy Metals In Selected Food Stuffs And Samples From Children And Their Effects On Health

In this paper,blood and urine samples from children and some food stuffs in Guiyang, Tongren and Wanshan,Guizhou Province,which have been seriously polluted by heavy metals,were chosen and the concentrations of four elements such as Se,Cd,Hg and Pb were determined by ICP-MS.Compared with the maximum allowance levels recommended by International Commission on Radiological Protection（ICRP）,the safty of some vegetable foods accumulated heavy metals was evaluated.Heavy metals effects on health were described with GSH,SOD,GPX and 8-OHdG and with SCGE technique.The results showed that the most suitable method in determination of heavy metals in whole blood and urine samples was established using interlabratory comparisons as criterion.The four trace elements like Hg,Cd,Pb and Se in the blood and urine from children and in local foods were determined.The concentrations of heavy metals in food indicated that most of the samples were higher in Wanshan than those in Guiyang.Cd and Hg concentrations in some food stuffs exceeded the national permitted hygienic limit while Pb concentration was lower than the standard.Among them,Cd and Hg were the most important contributors to heavy metal pollution in Guizhou province.Moreover,the health risk of Cd from food was calculated to be 1.07×10^-6·a^-1,while the non-carcinogenic risks levels were 10^-6·a^-1.Both were lower than the maximum allowance levels recommended by ICRP.The concentrations of Se,Cd,Hg,Pb in their blood and urine indicated that most of the trace elements had higher concentrations in Wanshan than those in Guiyang and Tongren,except Pb.But Pb concentration in five samples exceeded the relevant toxic levels.The correlation of Se and Hg was also discussed in the experiment.It was found GSH concentration,SOD and GPX activities in children’s blood in Tongren were higher than those in the other two palces.Moreover,it made conclusions that ICP-MS was established so as to exactly measure heavy metals,that heavy metals had been gradually accumulated in food and human body in high exposure areas but their contents could not rise up to serious injury on health and that the correlation between Se and Hg indicated Se antagonism against Hg damage.