Bioaerosol exposure during refuse collection: results of field studies in the real-life situation.

To determine the bioaerosol exposure of refuse collectors, field measurements were performed under real working conditions within the framework of a research project. Influencing variables such as different types of refuse, community structure, collection interval and season were taken into account. Overall, 1612 samples were taken in towns of Westfalia, Germany. With workplace levels on a scale of 10(3) to less than 10(4) CFU/m3 for the loader, the results show a surprisingly low total fungi concentration in comparison with earlier studies. Total bacteria concentrations, in contrast, were largely on a scale of 10(4) CFU/m3, with 10(5) CFU/m3 being registered sporadically, especially in apartment-block districts. Endotoxin levels were high especially in the summer months, occasionally reaching values of more than 50 EU/m3, whereas they were normally below 10 EU/m3 in autumn and winter. Inside the cab, the exposure level for the entire spectrum was at least one power of ten lower. The factors believed to account primarily for the low total fungi concentration were workplace hygiene, the prevailing 1-week collection interval, and the low in-process exposure time resulting from the effective deployment of automatic lifting devices. In contrast, the type of refuse was not found to have a significant influence.