The waste-collection and -processing industry in Europe is developing rapidly due to environmental constraints in the direction of separate collection, processing, and recycling of waste. It is likely that this will lead to an increase in the number of workers involved in the handling and processing of municipal waste, and an increase in the number of workers exposed to organic dust. This paper reports the results of an occupational hygiene study of the waste-collection and -processing industry (a compost-screening facility, a resource-recovery facility, and two waste-transfer facilities) in The Netherlands. It focuses on organic dusts, endotoxins, and microorganisms (total and gram-negative bacteria and fungi). Levels of exposure to inhalable organic dusts were highest in the waste-processing facilities (compost screening and resource recovery), with average concentrations for organic dusts up to 14.3 mg/m(3) during manual separation of waste and 9.7 mg/m(3) during compost screening activities. Personal endotoxin exposure was highest in the resource-recovery facility, ranging from 32.0 ng/m(3) for the supervisor to 131.1 ng/m(3) during manual separation of waste. High concentrations of microorganisms were found in all facilities. The highest levels for both total fungi and bacteria (<> 10&sup6; cfu/m(3)) were recorded in the dumping pit at the resource-recovery plant and in the dumping pit at one of the waste-transfer plants. It is concluded that high levels of exposures to microorganisms, and to a lesser extent organic dusts and endotoxins, are likely to occur in many processes and activities in the waste-transfer and -processing industry, and that the possibility of health effects due to these exposures cannot be excluded.