Worker Poisonings Due to Paraoxon Residues

Publisher Website
Google Scholar
Abstract
During June 1975, 3 poisoning incidents occurred among agricultural fieldworkers in Tulare County, California, USA. These incidents were attributed to exposure to residues of ehtyl parathion [a pesticide] on the foliage of orange trees and in the soil on the grove floor. In the incident groves, the paraoxon content of both the foliar and soil dust and the corresponding oxon-thion ratios were extraordinarily high. The paraoxon residues appeared to be remarkably persistent. Neither the formulated material nor the residues resulting from a subsequent experimental application of the same lot of pesticide contained abnormal amounts of paraoxon. A transient and unusual set of environmental conditions probably existed that affected the parathion residues and resulted in the abnormal production and persistence of paraoxon. Although the nature of these unusual environmental factors is not yet known, the results of preliminary work suggest that photochemical oxidants may have been involved. Regardless of the nature of the environmental conditions which produced these highly toxic residues, the fact that they appear to be rare and presently unpredictable places the reentry concept in some jeopardy as thesole means of worker protection. Where residue poisonings have been a recurrent problem, it may be necessary to supplement reentry regulations with some type of environmental standards based on foliar or soil residues.

This publication has 2 references indexed in Scilit: