EXPLANATORY MULTIVARIABLE MODEL FOR SPIROMETRIC ABNORMALITIES IN WETLAND FARMERS: CHRONIC ORGANOPHOSPHATE EXPOSURE AS A PRIMARY RISK FACTOR

Abstract

This study aims to identify environmental factors within the wetland ecosystem in Pemulutan District, analyze organophosphate pesticide exposure among rice farmers, and evaluate the association between pesticide exposure and worker characteristics with pulmonary function abnormalities and respiratory symptoms. A case-control study was employed, involving 106 respondents—53 rice farmers with abnormal pulmonary function and 53 with normal pulmonary function. Data were collected using a standardized questionnaire and pulmonary function tests conducted with a digitally calibrated spirometer. The findings revealed that the average annual rainfall in the study area was 220.8 mm, with a mean air temperature of 26.5°C and an average relative humidity of 84.5% (2014–2024). Bivariate analysis indicated that several variables were significantly associated with pulmonary function abnormalities, including: exposure duration >4 hours/day (p=0.001; Odds Ratio (OR)=6.272; 95% Confidence Interval (CI): 2.156–18.251), exposure frequency ≥3 times/week (p=0.004; OR=4.882; 95% CI: 1.677–14.210), respiratory symptoms (p=0.032; OR=2.946; 95% CI: 1.096–7.923), work duration ≥5 years (p=0.046; OR=2.021; 95% CI: 1.025–15.764), and age ≥35 years (p=0.026; OR=0.113; 95% CI: 0.017–0.773). The final logistic regression model identified exposure duration >4 hours/day as the primary predictor of pulmonary function abnormalities (p=0.001; OR=6.272; 95% CI: 2.156–18.251), after adjusting for age, exposure frequency, respiratory symptoms, and work duration. These results underscore that cumulative high-level exposure to organophosphate pesticides significantly increases the risk of impaired pulmonary function among rice farmers in wetland areas. This study is expected to serve as a foundation for occupational health risk management strategies for rice farmers working in wetland ecosystems.