Solid waste storage in specially designated areas – landfills – has been the basic method of municipal solid waste disposal management for many years. However, thermal treatment is the currently preferred method of solid waste disposal. Hygienic assessment of working conditions in municipal waste incineration plants is hindered due to the variability and complexity of pollutants emitted during the combustion process. For many years studies describing this problem have focused mainly on chemical pollution inside the plants as well as emitted into the atmosphere. Available data indicates the presence of organic dust at workplaces in the range 0.1–14 mg/m³. It has been proven that it is a carrier of a wide spectrum of microorganisms, including bacteria, fungi and both mesophilic and thermophilic actinomycetes as well as adenoviruses and torque teno virus (TTV). In the air, at workplaces, bacterial endotoxins have also been found in concentrations reaching even 50 000 EU/m³, which may significantly affect the occurrence of pro-inflammatory reactions in the lungs as well as toxic pneumonitis. Biological agents should be taken into account in the occupational risk assessment for harmful agents present in this environment, and an in-depth characterization of exposure and health effects resulting from contact with these agents should be continued to an even greater extent than before. Med Pr. 2019;70(1):99–105