Hygienic assessment of the quality of the drinking water from surface water sources in the Murmansk region

Introduction. The Murmansk Region is a highly industrialized region of the Russian Arctic. Therefore, the quality of its surface waters is significantly influenced by both climatic and geographical factors, as well as by mining activities. In light of this, it is an urgent priority to conduct a comprehensive hygienic assessment of the status of water supply sources in the urban areas within the region. Materials and methods. The yearbooks of the Main Geophysical Observatory named after A.I. Voeikov “The state of atmospheric pollution in Russian cities” for 2021–2022; state reports “On the state of sanitary and epidemiological welfare of the population in the Murmansk region” for 2021–2023, the results of laboratory studies of the surface water sources quality for 2018–2023; sanitary and epidemiological conclusions on the possibility of using water bodies for drinking and domestic water supply. A study was conducted on 13 surface water bodies in the Murmansk Region, which serve as sources of drinking water for 14 settlements in the region. Results. The most frequent excess of hygiene standards was observed in the following indicators: sanitary-chemical – Fe, Ni, Hg, Mn, NH4, benz(a)pyrene, phenol; generalized including chemical oxygen demand (COD), biological oxygen demand (BOD), permanganate oxidizability, pH; sanitary as microbiological – GCB, TCB, E. coli, coliphages. A list of indices has been determined for inclusion in the programs of industrial surface water sources quality control in the Murmansk region. The water treatment was determined to be provided only in 5 of the 13 water sources in the region with widespread disinfection. Chlorination is used at 11 of the 13 water sources, and ultraviolet irradiation is used at the other 2 ones. Limitations. In this research the list of indicators was limited by the research programs of social and hygienic monitoring and UGMS. Sampling points in the UGMS don`t correspond to water intake points in all settlements. Also, the results of laboratory tests of water before entering distribution networks aren`t considered in this work. In addition, the risk assessment was carried out taking into account the uncertainties associated with the fact that the population uses water after water treatment. The risk assessment in this situation was aimed at identifying priority indicators that need to be included in production control programs. Conclusions. The supervisory authorities are recommended to pay attention to the widespread excess of hygienic standards for sanitary-microbiological indicators in the Murmansk region`s drinking water to prevent outbreaks of infectious diseases with aquatic transmission.