Accumulation of Heavy Metals in Vegetables Grown Around an Industrial Area in Foshan

The concentrations of Zn,Cu,Pb and Cd in edible part of vegetables and corresponding surface soil samples collected from the fields near an industrial area in Foshan were investigated to evaluate safety for human consumption and calculate accumulation factors,i.e.the ratio of metal concentration(fresh mass) in edible part of vegetable to the total metal concentration in soil.The results indicated that the contents of Zn,Cu,Pb and Cd in vegetables were less than the national tolerance limit in foods with the exception of two water spinach(Ipomoea aquatica) samples for Pb and one spring onion(Allium fistulosum)sample for Cd.The accumulation factors of Zn,Cu,Pb and Cd in vegetables decreased in the order of CdZnCuPb.The accumulation factors of heavy metals for different vegetable species were significantly diffrerent,and the order was leafy vegetables gourd vegetables.Significant correlations did not exist between the heavy metal concentrations in soil and vegetable samples excepting Zn.With respect to food safety for human consumption,gourd vegetables are more suitable grown than leafy vegetables in this area.