Long-term occupational exposure to soil-applied malathion and its consequences for oxidative stress and acetylcholinesterase activity in cucumber greenhouse workers: A cross-sectional study

Document Type : Research Paper

Authors

1 Department of Biology, Alikhan Bokeikhan University 11 Mangilik El str., Semey, the Republic of Kazakhstan

2 Department of Agricultural Sciences, Zhangir Khan West Kazakhstan Agrarian and Technical University, 51 Zhangir Khan str., Uralsk, 090009, the Republic of Kazakhstan

3 NAO “Shakarim University" 20A Glinka str., Semey, 071404, the Republic of Kazakhstan

4 Department of Biology, M.Kh. Dulaty University 13 Y.Suleimenova str., Taraz, 080000, the Republic of Kazakhstan

10.22124/cjes.2026.9739

Abstract

Malathion is known to cause oxidative stress and block the action of acetylcholinesterase (AChE). This study aimed to investigate how working with this pesticide affects antioxidant enzymes (SOD and CAT), malondialdehyde (MDA), and AChE levels in cucumber greenhouse workers.  This cross-sectional study included 60 male workers with at least one year of exposure and sixty age- and body mass index-matched unexposed individuals. The SOD and CAT enzyme activity of erythrocytes and MDA and AChE levels of blood serum were determined by the spectrophotometric method.  We compared the two groups; the exposed workers had lower levels of SOD (5.34±0.55 vs. 6.26±0.74 U/mg protein; p<0.001), CAT (24.10±2.73 vs. 26.79±2.76 U/mg protein; p<0.001), and AChE (3307±372 vs. 4712±371 U/L; p<0.001). Their MDA levels were higher too (1.58±0.27 vs. 1.17±0.23 nmol/ml; p<0.001). Strong correlations were observed only in the exposed group: MDA went up as CAT went down (r=-0.91), same for MDA and SOD (r=-0.75), and SOD dropped along with AChE (r=0.75). All of these were statistically significant (p<0.001).  Chronic occupational exposure to soil-applied malathion is associated with increased oxidative stress and suppressed antioxidant defenses, and inhibition of the enzyme AChE. These findings underscore the need for better protective measures and biological monitoring. However, causality cannot be established due to the cross-sectional design. Longitudinal studies with direct biomonitoring are warranted to confirm causality.

Keywords


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