An investigation on harmful substances in vegetables in Linyiprefecture

The residues of tbe main harmful substancessuch as nitrate, nitrite,666,DDT and six heavy metals in veg-etables at selected spots in Linyi prefecture have been detect-ed. The results show: nitrates are the main harmful sub-stances. Among the three vegetables detected,the rate of ni-trate and nitrite exceeding standard are 78.3%and 33.6%separately.Most of the contents of heavy metals in the vegeta-bles are below the sanitary standards. DDT are not detectedand the average rate of 666 exceeding standard is 4.3%.