Radiotracer study on residues and residue distribution of zineb in plant-soil system

In view of the widespread use of zineb on food plants and the toxicity of one of its metabolites, ETU, a study on the residues and residue distribution of zineb and ETU in plant-soil systems was carried out. The half-life values for total zineb residues on egg-plant leaves and in soil were observed to be over three and two weeks, respectively. Egg-plant skin contained higher amount of zineb residues than the fruit pulp. Washing with water greatly reduced zineb residue levels, especially those in the fruit skin. Compared with zineb, ETU is much easier to be uptaken by plants and to leach into deeper layer of soil due to its high water solubility. Therefore, attention should be paid to the contents of ETU in zineb formulations as impurity and formation of ETU in the environment.