Residues of quintozene, its contaminants and metabolites in soil, lettuce, and witloof-chicory, Belgium--1969-74.

Authors studied contamination of soils used to raise lettuce in greenhouses and witloof-chicory (French endive) in forcing beds. The crops had been treated with the fungicide quintozene; residues detected included quintozene, its technical impurities and metabolites hexachlorobenzene, pentachlorobenzene, pentachloroaniline, and pentachlorothioanisole. Analyses of 72 soil samples indicated that soils remain contaminated with these chemicals one or more years after application. This is attributed to the high persistence of quintozene, its impurities and metabolites, and the almost annual application of the fungicide. Analyses of the crops show that quintozene, hexachlorobenzene, and pentachloroaniline are taken up from contaminated soils, especially by lettuce. Pentachlorothioanisole, although present in the soils, was not detected in the crops.