The health status of northern Omo State Farm workers exposed to chlorpyrifos and profenofos.

The health effects of organophosphorus (OP) pesticides on cholinesterase (ChE) activities were assessed among 81 pest control workers from Northern Omo State Farm (Ethiopia), following the occupational use of Chlorpyrifos 25 and 48% ULV and Profenifos 250 EC/ULV. Plasma ChE (PChE) and erythrocyte ChE (AChE) activities were determined electrometrically before and after pesticide exposure. Plasma alkaline phosphatase (AP) and glutamic pyruvic transaminase (GPT) values were estimated colorimetrically. Risk factors of pesticide poisoning and related occupational factors were assessed following the WHO recommendations. The mean PChE and AChE activities determined after pesticide exposures were significantly lower than the pre-exposure values (P < 0.05); 16% and 40% of the pest control workers had PChE and AChE levels below 50% of the pre-exposure values, respectively. The mean plasma AP and GPT values were found to be within the recommended normal limits. No significant difference in either of the ChE activities was observed between the spray men and the pest assessors, although the former were believed to have frequent contact with the concentrated OP formulations. Risk factors of pesticide poisoning such as workers ignorance about the toxicity of pesticides, poor personal hygiene and total absence or improper use of personal protective devices were prevalent. Measures that should be considered to minimize the problem in the farm population are recommended.