Airborne Bacteria from Wastewater Treatment and Their Antibiotic Resistance: A Meta-Analysis

The treatment of domestic and industrial wastewater is a source for a large number of airborne microorganisms, which can be released at the environment during mechanical aeration. A meta-analysis of up to 14 industrial and municipal treatment plants was performed to determine the bacterial count in bioaerosols, as well as antibiotic resistance, at different stages of the wastewater treatment (pretreatment, primary, secondary and tertiary treatment), in comparison with bacterial counts of the ambient air surrounding the treatment plants. The highest contamination of the air with microorganisms was observed in the raw sewage inlet and at the biological reactor. In most analyzes, the air in the wastewater treatment plant was characterized by a higher content of microorganisms than at the control point. Bioaerosols from water treatment might be an important source of antibiotic resistance genes, which can be transported considerable distances and can represent a potential risk to humans. Therefore, employees should recognize the health risks associated with the absence of personal protective equipment, such as masks or respirators.