Analysis on nitrate polluttion of vegetable in Pudong area Shanghai

Vegetable samples of sewage-irrigated region and plantations were investigated for nitrate content in Pudong New District,Shanghai.It was showed the nitrate content of the greenhouses were higher than that of the air-open soil.And vegetables easily absorb nitrogen,which average content of nitrate was high to 785.43 mg/kg,as melon and eggplants were followed.There was a decreasing order of leaf vegetables melon(67.10 mg/kg)eggplants(26.56 mg/kg).Most nitrate content was higher in sewage-irrigated region than others.According to the edible safety assessment,some vegetables were heavily polluted,which was exceeding first class standard for high content of nitrate,accounting for 46.67%.And some reached to third class polluted level,such as swamp cabbage,greengrocery,amaranth and so on,especially some vegetable third class index was to 1.28.