Associations between acute symptoms and bioaerosol exposure during the collection of household waste

BACKGROUND: A study was performed to investigate associations between work-related symptoms and bioaerosol exposure in 22 workers collecting waste separated at source and mixed household waste. METHODS: Full work shift exposures to bacteria (spherical and rod-shaped) fungal spores, endotoxins, and total dust were measured. Symptoms experienced during work on the day that exposure was measured were recorded by use of a short questionnaire. Questions were posed on respiratory symptoms, systemic effects such as headache, tiredness, and gastrointestinal symptoms. RESULTS: The median exposure levels of bacteria and fungal spores were 0.4 and 0.1 x 10(6)/m3, respectively. The exposure to rod-shaped bacteria (7% of the bacteria count), endotoxins (1.8 EU/m3), and dust (0.2 mg/m3) was low. The symptoms most often reported were unusual tiredness (24%), headache (22%), cough (15%), and irritation in eyes and nose (10 and 17%). These symptoms were also found to be associated to microbial components. CONCLUSIONS: The results suggest that acute work-related nose irritation is associated with exposure to bacteria. Rod-shaped bacteria were also associated with nose irritation and unusual tiredness. It is likely that cough is associated to fungal spores, while other associations which were found could be due to confounding.