Concentration analysis and health risk assessment of heavy metals in vegetables of Beijing suburban

In order to assess human health risk posed by elevated concentrations of heavy metals including chromium,cadmium,copper and zinc in vegetables,a survey of heavy metals levels in vegetables planted in suburban areas of Beijing was conducted.154fresh vegetable samples were obtained.The heavy metals contents of Cr,Cd,Cu and Zn in vegetables were measured using atomic absorption spectrometer(AAS).The results were compared with main vegetable standards of China.Possible health risks to local residents caused by the heavy metals through consumption of vegetables were assessed based on target hazard quotient(THQ),and THQ values between adults and children were compared.Results showed that the average contents of Cr,Cd,Cu and Zn in vegetables were 0.210mg/kg,0.0123mg/kg,1.034mg/kg and 3.343mg/kg,in which the four heavy metals were all in line with Chinese national food safety standards,while Cr content in part of root vegetables exceeded.THQs of Cr,Cd,Cu and Zn for adults due to consumption of vegetables were 1.123,0.199,0.419and 0.181,while for children were 1.490,0.262,0.550and 0.237,and both of which had potential health risks from Cr.Total metal THQs for adults and children were 1.932and 2.539,which were mainly caused by Cr.Single heavy metal contribution rate to the combined risk was basically the same for adults and children,but health risks for children caused by heavy metals were bigger than adults.