Article Toxicology and Industrial Health 2022, Vol. 38(6) 342–350 © The Author(s) 2022 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/07482337221096315 journals.sagepub.com/home/tih Occupational risk assessment of organophosphates with an emphasis on psychological and oxidative stress factors Ali Fghihi-Zarandi 1 , Fatemeh Dabaghzadeh 2 , Ali Vaziri 3 , Somayyeh Karami-Mohajeri 2,4 , Behnam Ghorbaninejad 4 , Ahmadreza Zamani 5 and Karim Rahimi-Sadegh 6 Abstract Organophosphate pesticides (OPPs) are widely used all over the world in domestic and industrial settings, but these chemicals affect the nervous system, induce suicidal thoughts, depression and anxiety, and impair sleep quality. The purpose of this study was to investigate the relationship between the main toxicity mechanisms of OPPs, oxidative stress and cholinesterase inhibition, and psychological parameters in chronic exposure to OPPs. This cross-sectional study was conducted on 56 male OPPs factory workers as the worker group and 47 unexposed individuals within the same age range as the control group. Psychological factors were assessed using validated questionnaires. The activity of plasma cholinesterase and oxidative stress biomarkers, total antioxidant capacity of plasma, lipid peroxidation (LPO), and protein carbonylation were determined in blood samples by spectrophotometer. Sleep quality score in the factory workers was lower, and depression and suicidal ideation scores were higher than those in the control group. These factory workers showed 35% lower levels of plasma cholinesterase activity than did the controls. Compared to the control group, a significant impairment in oxidative stress biomarkers was also observed in the workers. Meanwhile, there was a significant relationship between the duration of employment and the level of LPO as well as a significant correlation between the quality of sleep and plasma cholinesterase in the workers. In conclusion, long-term exposure to OPPs could cause oxidative damages and neurobehavioral effects. The close monitoring of workplace exposure to organo- phosphates pesticides and also their respective solvents along with the reduction of working hours are of the necessities to avoid the adverse impacts of exposure to these pesticides. Keywords Acetyl cholinesterase, nervous system disorders, organophosphorus, oxidative stress, pesticides Received 17 September 2021; Revised 2 March 2022; Accepted 5 April 2022 1 Department of Occupational Health Engineering, School of Public Health, Kerman University of Medical Sciences, Kerman, Iran 2 Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran 3 Department of Chemical and Petroleum Engineering, Science and Research Branch of Islamic Azad, Tehran, Iran 4 Departments of Toxicology and Pharmacology, School of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran 5 Vice_chancellery of Health, Kerman University of Medical Sciences, Kerman, Iran 6 Occupational Health Office, Kavosh Kimia Kerman Company, Kerman, Iran Corresponding author: Somayyeh Karami-Mohajeri, Faculty of Pharmacy, Kerman University of Medical Sciences, Haft Bagh-e-Alavi Highway, Kerman 7616911319, Iran. Email: somayyehkarami@gmail.com; s_karami@kmu.ac.ir