Propanil-chloracne and methomyl toxicity in workers of a pesticide manufacturing plant.

In a survey of occupationally acquired disease in workers at a pesticide plant, we found that 11 (11%) of 102 workers had been hospitalized for illness related to chemical exposures; highest hospitalization rates occurred in packaging (27%), production (22%), and maintenance (9%) workers. Commonest causes of hospitalization were intoxication by the carbamate pesticide methomyl [1-(methylthio)ethylideneamino methyl carbamate], a reversible cholinesterase inhibitor, and methemoglobinemia following exposure to 3,4-dichloroaniline. On clinical evaluation, five (46%) of 11 packaging workers, the group with the highest exposure to methomyl, had experienced blurred vision or pupillary constriction. Seventeen (61%) of 28 production workers with exposure to dichloroaniline and propanil (3'4'-dichloropropionanilide) had chloracne, an acne-form dermatosis caused by the contaminant tetrachlorazobenzene in propanil and dichloroaniline. The chloracnegenic potentials of propanil and dichloroaniline were verified by rabbit ear tests. These findings reemphasize the hazards inherent in the the manufacture and formulation of pesticides and herbicides.