Hygienic Assessment of the Iron Content of Tap Water in Administrative Centers in the North of the Tyumen Region

Abstract

Background: Introduction: Iron is an essential mineral for humans. Its excessive dietary intake has no adverse health effects but high exposure to inorganic iron can induce oxidative stress. Increased Fe concentrations in tap water in the north of the Tyu­ men Region are attributed, on the one hand, to natural characteristics of its source and, on the other hand, to iron released by deteriorated water pipes. In the administrative centers of this region, high-quality reagent-free water treatment is carried out but tap water quality is largely influenced by the condition of water supply networks with the wear indicators of 26.3 % and 82.1 %, in the cities of Khanty-Mansiysk and Salekhard, respectively. Objective: To compare iron contents in tap water in Khanty-Mansiysk and Salekhard against its maximum permissible concentration and to assess health risks from exposure to this mineral in drinking water. Materials and methods: Fifty tap water samples were taken in each of the two administrative centers of the Tyumen Region (Khanty-Mansiysk, Khanty-Mansi Autonomous District – Yugra, and Salekhard, Yamalo-Nenets Autonomous District) for a spectrophotometric analysis of iron. The results were evaluated according to regulations SanPiN 1.2.3685–21, Hygienic stan­ dards and requirements for ensuring safety and/or harmlessness of environmental factors to humans, introduced by Decree No. 3 of the Chief State Sanitary Doctor of the Russian Federation of January 28, 2021. Non-carcinogenic risks were assessed in accordance with Guidelines R 2.1.10.1920–04, Human health risk assessment from environmental chemicals. Results: Iron levels in tap water were found to be significantly lower in the city of Khanty-Mansiysk compared to Salekhard (p = 0.002) with excessive Fe concentrations established in 10 % and 66 % of the samples taken in those cities, respectively. Ac­ cordingly, the Fe-related hazard quotient in Khanty-Mansiysk was almost twice as low (0.73) as in Salekhard (1.52) indicating increased likelihood of a toxicological response to the chemical in the latter. Conclusions: In order to supply residents with drinking water of optimal quality and reduce potential health risks, it is neces­ sary to replace worn out distribution networks, organize and ensure proper monitoring of water quality, duly implement the Regional Clean Water Project and assess its effectiveness.