Erythrocyte Acetylcholinesterase Enzyme Activity, Serum Interleukin-6 Level and Respiratory Function of Myanmar Agricultural Workers Exposed to Organophosphate Pesticides
Background and Aim: Myanmar is one of the countries in production of agricultural plant commodities. Nowadays, pesticides are commonly used to increase agricultural production and productivity. Organophosphate pesticides exposure can cause many physiological changes within the body including impaired respiratory function. Therefore, the present study aimed to find out the relationship between the erythrocyte acetylcholinesterase enzyme activity, serum interleukin-6 level and respiratory functions such as forced expiratory volume in first second (FEV1), forced vital capacity (FVC), ratio of forced expiratory volume in first second and forced vital capacity (FEV1/FVC), peak expiratory flow (PEF) and average forced expiratory flow between 25% and 75% of FVC (FEF25-75%) among agricultural workers who exposed to organophosphate pesticides and non-exposed control subjects. Methods: A community-based cross-sectional, comparative study was done in agricultural workers (n = 40) who live in A-lal-chaung village, Magway Township and age/BMI matched non-exposed subjects (n = 40) who live in Yan-Way Quarter, Magway Township. All the participants were selected according to inclusion and exclusion criteria by simple random sampling method. Erythrocyte acetylcholinesterase (AchE) enzyme activity was measured by spectrophotometric method and serum interleukin-6 levels were measured by enzymelinked immunosorbent assay (ELISA) method. Respiratory function parameters were measured by Spirobank II spirometer. Results: The mean erythrocyte acetylcholinesterase enzyme activity was significantly lower in exposed group than that of non-exposed group (3354.43±589.81 U/L vs 4515.83±759.33 U/L; p<0.001). The percentage of predicted value of respiratory function parameters of exposed group were significantly lower than that of non-exposed group (FEV1: 72.13±4.40 vs 75.95±4.05; FVC: 66.90±4.40 vs 70.60±4.20; FEV1/FVC: 110.35±2.69 vs 111.32±1.33; PEF: 5.52±8.66 vs 79.40±5.09) (p<0.05). There were significant positive correlation between erythrocyte acetylcholinesterase activity and respiratory function parameters in all groups (n=80) (FEV1: r=0.425, p<0.001; FVC: r=0.301, p<0.05 and PEF: r=0.316, p<0.05). There were significant negative correlation between erythrocyte acetylcholinesterase activity and serum IL-6 level (r= -0.374, n= 80, p<0.05). Serum IL-6 level was significantly higher in exposed group than non-exposed group (34.77±3.3 pg/mL vs 28.75±2.0 pg/mL; p <0.001). There was a significant negative correlation between serum IL-6 level and respiratory function parameters in all group (n=80) such as FEV1 (r= 0.300, p<0.05) and FVC (r= 0.331, p<0.05). Conclusion: It was concluded that agricultural workers who exposed to organophosphate pesticides have higher serum IL-6 level and lower respiratory functions than that of non-exposed subjects. The present findings highlighted that there has an impact of chronic low dose OP exposure on respiratory health and there has a role of IL-6 in respiratory function decline.