Exposure to micro-organisms and dusts during refuse collection.

A one-year-study was aimed to investigate the exposure of sanitation agent to airborne mould fungi and dust during refuse collection. The study included the sanitation agent of a specific rural district in the North of Germany. The results showed that, irrespective of the technical equipment of the refuse collection vehicles, the sanitation agent's exposure to airborne microorganisms was continuously high, with shift means varying between 10 4 and 10 5 colony-forming units (CFU)/m 3 in winter and between 10 5 and 10 6 CFU/m 3 during the warmer seasons. In some cases peak exposure to mould fungi could come to 10 7 CFU/m 3 . It was possible to prove that the germs emitted at the dustbin-tipping device formed dust clouds as soon as the collection vehicle started moving. It became apparent that swirled particles of inhalable dust sedimented on the tipping device as well as leaks in the vehicle structure play a central role in the exposure problem. While riding on the footboard, the sanitation agents were exposed to dust and germ concentrations which exceeded the shift means by an order of magnitude. A rapid dilution of the hazardous concentration by clean environmental air, as was described for instance in connection with workplaces in the composting industry, could not be shown for this type of workplace.