Concentration Analysis and Health Risk Assessment of Heavy Metals in Vegetables at A Sewage Irrigation Area of Nanjing City

Pb,Cr,Zn and Cu contents in 6 vegetable samples from a sewage irrigation area of Nanjing City were detected by flame atomic absorption spectrometry,and 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 contents of Pb were in line with Chinese pollution-free green vegetables standard,while Cr,Zn and Cu contents exceeded.Both of adults and children had potential health risks from Cr and Cu.Total metal THQs for adults and children were 11.857 and 15.569,respectively,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.