Secondary Contamination of Pesticide Applicators during Spraying Operations on Eggplants

Abstract

A contamination of cypermethrin seen in its applicators was investigated in an eggplant field. The pesticide was sprayed forward or backward along the furrows. In a grower's field, the exposure was low when the applicators went along the furrow by spraying forward. On the other hand, a considerable exposure was highly detected on the most part of the body when they returned along the furrow. The similar exposure was occurred when spraying backward, especially at the back of the applicators. Next, shoots of V-shaped training, carrying neither flowers nor young fruits, were extensively pruned in order to decrease the contact with the applicators. After pruning, 480 leaves were decreased to 60 and 143 shoots to 27 for each 100m-furrow at 80cm from shores and at 150-160cm above the soil surface. This strong pruning led to the successful reduction in the exposure of the applicators at both walk-directions (going and returning) and at both spraying-methods (forward and backward). Furthermore, the exposure was reduced to the minimum in a model experiment using screen clothes to prevent applicators from contacting shoots and leaves. These results indicate that the exposure of the human body to the pesticide in eggplant fields mainly resulted from the secondary contamination due to the pesticide deposited on the leaves and shoots. Pruning of shoots will be the most important method to reduce the exposure of applicators to pesticides in order to avoid a direct contact.