Respiratory symptoms in Ecuadorian workers associated with informal labor and cantonal satellite pollution metrics.

INTRODUCTION

Evidence on the association between ambient pollution and occupational hazards in Ecuador remains limited. This cross-sectional study evaluated the association between working conditions, satellite-derived ambient pollutants, geographic factors, and respiratory symptoms.

METHODS

We analyzed 1,807 workers across four sectors. Respiratory symptoms (ECRHS) were cross-referenced with Sentinel-5P telemetry, utilizing z-score standardized environmental variables and selecting optimal spatial/temporal concentration percentiles (p25, p50, p75, and p95) via the Akaike Information Criterion (AIC) for each outcome. Multivariable penalized logistic regression (Firth's method) identified factors associated with respiratory symptoms.

RESULTS

Informal employment showed the strongest association with respiratory symptoms, including asthma (aOR 12.56; 95% CI: 5.09-32.87), wheezing (aOR 6.78; 95% CI: 1.83-27.89), chronic cough (aOR 4.14; 95% CI: 2.26-7.74), and chronic phlegm (aOR 2.53; 95% CI: 1.39-4.67). Direct workplace chemical inhalation, compounded by a complete lack of risk awareness, was associated with significantly higher odds for asthma, wheezing, and chronic cough. Geospatially, after controlling for canton-level altitude-which acted as an independent protective factor against asthma (aOR 0.78; 95% CI: 0.66-0.93)-nitrogen dioxide (NO2) and sulfur dioxide (SO2) emerged as the primary independent environmental predictors for chronic phlegm and cough, while ozone lost statistical significance.

DISCUSSION/

CONCLUSION

Informal employment and unprotected chemical inhalation are strongly associated with respiratory symptoms, frequently exceeding the risks observed in traditional high-exposure sectors. Furthermore, regional atmospheric pollution showed a significant statistical association with chronic respiratory outcomes at the cantonal level. Integrating high-resolution aerospace monitoring into occupational health surveillance represents a potential strategy to address these overlapping structural vulnerabilities; however, causal inference remains limited by the cross-sectional design.