Respiratory health outcomes, rhinitis, and eczema in workers from grain storage facilities in Costa Rica

Objectives: To examine the associations of inhalable grain dust exposure with respiratory health outcomes, rhinitis, and eczema reported by workers from rice, wheat, and maize storage facilities. Methods: A cross-sectional study of 136 workers (73 operators and 63 administrative staff and other workers) from eight Costa Rican grain storage facilities was conducted in 2014–2015. Full-shift personal inhalable dust samples from all workers were collected. Study participants were administered a short version of the European Community Respiratory Health Survey questionnaire to identify symptoms of asthma, chronic bronchitis, rhinitis, and eczema. Associations between grain dust exposure and health outcomes were assessed using multivariable logistic and negative binomial regression models adjusted for age, smoking history, grain type, and presence of pets or farm animals in the home. Results: The median inhalable grain dust concentration was 2.0 (25th to 75th percentile: 0.3–7.0) mg m⁻³. Higher concentrations of inhalable dust were associated with increased odds of (i) asthma symptoms or medication use [adjusted Odds ratio (OR_a) per 10-fold increase in dust concentration 2.7; 95% confidence interval (CI): 1.3–6.7]; (ii) a score of at least two out of five symptoms suggestive of asthma (OR_a 1.2; 95% CI: 1.0–1.3); and (iii) eczema (OR_a 3.6; 95% CI: 1.7–9.6). No associations of inhalable grain dust exposure with chronic bronchitis and rhinitis were observed. Conclusions: High exposure to inhalable dust in Costa Rican grain storage facilities was associated to asthma symptoms and eczema in workers.