Minimizing occupational exposure to pesticides: Techniques for establishing safe levels of foliar residues

Field workers hand harvesting, stripping, thinning, disbudding, pruning, and pinching crops come into contact with toxic organophosphate residues on foliage. These residues inhibit Cholinesterase activity, causing dizziness, pinpoint pupils, nausea, headache, and other symptoms which, if severe enough, lead to hospitalization and/or loss of work. To reduce these hazards, the California Department of Agriculture in 1971 established reentry intervals for 16 organophosphate1 insecticides. This list has been expanded over the last eight years to include 21 organophosphate insecticides used on vine and tree fruits as indicated in Table I.