Health risk assessment of glyphosate exposure among rubber farmers in northeast Thailand

Rubber farmers exposed to herbicides containing glyphosate face significant health risks from occupational exposure. This study aimed to investigate the prevalence of health symptoms and their association with glyphosate exposure among rubber farmers in northeast Thailand. A cross-sectional study was conducted to investigate the prevalence of health symptoms using a self-report questionnaire. Of 400 participants, 72.8% reported chemical exposure during spraying and 39.3% reported adverse health effects. The most frequent symptom was nasal irritation (18.5%), followed by coughing or shortness of breath and fatigue with 3.75%. After adjustment, reporting any adverse health effect was associated with age > 40 years (aOR 2.02; 95%CI 1.09,3.74; P = 0.025), male sex (aOR 1.83; 95%CI 1.19, 2.82; P = 0.006), >10 years’ experience (aOR 1.53; 95%CI 1.01, 2.31; P = 0.043) and underlying disease (aOR 1.75; 95%CI 1.10, 2.79; P = 0.019). Unsafe practices and equipment problems were strongly associated with higher odds: self‑application (aOR 1.97; 95%CI 1.24, 3.13; P = 0.004), leaking equipment (aOR 2.50; 95%CI 1.62, 3.86; P < 0.001), wet clothing while spraying (aOR 2.79; 95%CI 1.78, 4.36; P < 0.001), eating during work (aOR 2.07; 95%CI 1.30, 3.29; P = 0.002) and morning spraying (aOR 2.88; 95%CI 1.38, 6.03; P < 0.005). The study revealed a high prevalence of health effects among rubber farmers, with the strongest risk magnitude linked to unsafe practices and equipment. Providing personal protective equipment, guide occupational health and training on chemical handling practices is crucial for reducing these risks effectively.