Fountains as potential sources of aerogenic risk for urban populations

Abstract

Introduction. Fountains (office and outdoor), being small decorative structures used to improve the parameters of the human life environment, in the process of their work during the generation of a water jet, determine the creation of spray and aerosol fractions, thereby allowing the loss of a certain volume of liquid when air moves and wind carryover. The biological safety of the operation of such hydraulic structures depends on the composition of the microflora of the water in the main reservoir of the fountain, especially in the warm season. Materials and methods. For the period 2010-2020, the study of the composition of the microflora of water in the main reservoirs of the existing fountains and in the sedimented spray-aerosol mixture formed during the operation of these hydraulic structures was carried out. Results. At water temperatures above +18 °C and the absence of a disinfection system or its regular complete replacement, fountains were found to have a significant level of contamination with bacterial and fungal pathogens, including mycobacterium tuberculosis; the number of microorganisms of the E. coli group in office and open city fountains. The amount of Clostridial flora and streptococci in open fountains significantly exceeds the standard indicators (p <0.05). Limitations. When studying the trends in concentration of liquid particles in the air, the methodology of K.Y. Kondratiev et al. (1988) and V.M. Khvata et al. (1991) was used. The studies were carried out in accordance with the Interstate standard “Water. Methods of sanitary and bacteriological analysis for field conditions” GOST 24849-2014, 2016. Conclusion. The microflora of the operating fountain, in the absence of disinfection of water or its regular replacement, is characterized by a high titer of bacteria of the E. coli group, streptococci, staphylococci, mycobacterium tuberculosis, mold and yeast fungi. The one of the conditions for the excessive growth of these microorganisms in this hydraulic system is the water temperature above 18 °C. In the sedimented aerosol near the active fountain, a bacterial and fungal spectrum of pathogenic microorganisms similar to the water is found. Fountains (external and office) can be considered as sources of aerogenic household infection of the population of modern cities, which requires strict adherence to sanitary norms and rules that ensure the biological safety of these hydraulic structures.