Objectives: To prospectively assess respiratory health in wastewater workers and garbage collectors over 5 years.
Methods: Exposure, respiratory symptoms and conditions, spirometry and lung-specific proteins were assessed yearly in a cohort of 304 controls, 247 wastewater workers and 52 garbage collectors. Results were analysed with random coefficient models and linear regression taking into account several potential confounders.
Results: Symptoms, spirometry and lung-specific proteins were not affected by occupational exposure.
Conclusions: In this population no effects of occupational exposure to bioaerosols were found, probably because of good working conditions.