[Frontiers in Bioscience S3, 393-407, January 1, 2011]

Emission of bacteria and fungi in the air from wastewater treatment plants - a review

Ewa Korzeniewska

Department of Environmental Microbiology, Faculty of Environmental Sciences and Fisheries, University of Warmia and Mazury, Olsztyn, Poland


1. Abstract
2. Introduction
3. Air pollution
3.1. Bioaerosol
3.2. Meteorological factors and bioaerosol concentration
3.3. Assessment methods for bioaerosol
4. Wastewater treatment plants as a source of microorganisms 4.1. Bacteria, moulds and yeasts in the sewage and sludge
4.2. Pathogenic and potentially pathogenic microorganisms in the sewage
4.3. WWTPs as a source of bioaerosols 5. Bioaerosols and human health risk
6. Summary
7. References


An increase in global population, coupled with intensive development of industry and agriculture, has resulted in the generation and accumulation of large amounts of waste around the world. The spread of pathogenic microorganisms, endotoxins, odours and dust particles in the air is an inevitable consequence of waste production and waste management. Thus, the risk of infections associated with wastewater treatment plants (WWTPs) has become of a particular importance in recent decades. Sewage and unstable sludge contain various pathogens such as viruses, bacteria, and human and animal parasites. These microorganisms can be transmitted to the ambient air in wastewater droplets, which are generated during aeration or mechanical moving of the sewage. Bioaerosols generated during wastewater treatment may therefore pose a potential health hazard to workers of these plants or to habitants of their surroundings. The degree of human exposure to airborne bacteria, fungi, endotoxin and other allergens may vary significantly depending upon the type and the capacity of a plant, kind of the facilities, performed activities and meteorological conditions.