Hygienic efficiency of ultraviolet disinfection of water in centralized drinking and household water supply systems (systematic review)

Introduction. Drinking water supplied to the population must be safe in epidemic terms. However, some viruses and parasites are resistant to the disinfecting effect of traditionally used agents for water treatment. The use of UV irradiation ensures the microbiological safety of water, but there are factors affecting its effectiveness. The purpose of the review was to systematize scientific data on the effectiveness of the use of UV irradiation in relation to drinking water. Materials and methods. The search for scientific publications was carried out using literature databases MedLine/PubMed, Scopus, and Science Direct. The total number of publications was one thousand six hundred forty-six. The criteria for including the report in the systematic review were: publications in Russian or English with an available full-text version; samples for the study are water from centralized water supply systems or specially prepared microorganisms; any type of research evaluating the effectiveness of a wide range of doses of UV irradiation against microorganisms. Results of the analysis of publications. A systematic review included 17 reports about the effect of UV irradiation on bacteria and viruses. The subject of several studies was the resistance of protozoan cysts and helminth eggs to different doses of UV irradiation. According to the results presented in the publication, pathogenic viruses and bacteria, giardia cysts possess of the least resistance to UV irradiation (100% inactivation). 4 log-inactivation was established for Mycobacteia. E. coli and coliphages demonstrate a wide range of indicators of the resistance to ultraviolet radiation due to the diversity of the studied strains. Conclusion. UV disinfection should be used as an additional method in combination with traditional reagents methods of water treatment. It is necessary to study the effect of UV irradiation on helminth eggs and protozoan cysts.