POEM model application feasibility with Diazinon poison using cholinesterase activity level measurement of farmers in the west regions of Iran

Abstract

Introduction: The most common occupational exposure among farmers is exposure to pesticides. Organophosphate pesticides (OP) are widely used to control pests in agriculture. The main mechanism of Organophosphates (OPs) toxicity is irreversibly inhibiting of Butyl cholinesterase and acetyl cholinesterase. POEM model (Predictive Operator Exposure Model) was made to assess exposure to and absorption of the pesticides. The aim of this study was to estimate exposure to the organophosphates using POEM model and to compare its results with activity level of plasma cholinesterase (PChE) among farmers in the west regions of Iran. Material and method: In this descriptive and analytical research, farmers were divided into two same groups who were exposed to diazinon. One group of them wore full personal protective equipment (PPEs) and the second group including farmers with daily routine work had no proposed personal protective equipment. Before and after spraying operation, a blood sample was collected from both groups of farmers, as well as from control group. Then, plasma cholinesterase activity was measured by DGKC (German Biochemical Society) and photometric device. Farmer's exposure to OPs was estimated with POEM model. Results: The activity mean PChE enzyme in the groups with and without personal protective equipment was 11639.3 mg/l and 8516.3 mg/l, respectively. The predicted mean total absorbed dose and predicted total exposure to the toxic substance in group with PPEs was 9.1 mg/day and 0.15 mg/kgbw/day, respectively and in the group with PPEs were 0.5 mg/day and 0.009 mg/kgbw/day, respectively. Using of the POEM model, dermal exposure average, percentage of dermal absorption, absorbed dose at the time of preparing the poison solution and spraying was significantly higher in the no PPE group as compared to the PPE group (P<0.001). Conclusion: This study showed that the use of personal protective equipment prevents from the effects appearing of pesticides by reducing the activity of PChE. With the increasing in PChE activity, the values of POEM model parameters decreases such as the absorbed dose of the skin and the inhalation of the toxin. Therefore, the POEM model can be used to check the exposure of people with pesticides. Finally, this study suggests that the POEM model can be considered as a screening tool to identify individuals at exposure of pesticides to the next steps for biological monitoring, diagnosis and treatment.