Danchyshyn M. Experimental study of the effect of nitrates on the rats of various ages under the conditions of their intake with drinking water

The dissertation provides a theoretical generalization and presents the results of solving an actual scientific task, which consists in establishing the degree of risk to the health of the population of different age categories when drinking drinking water with an excess of nitrate content and in clarifying the age-related characteristics of the action of nitrates under the condition that they are received from drinking water on the cellular composition of peripheral blood, hematopoiesis, the functional state of the liver, the peculiarities of metabolic process disorders and the antioxidant system in the body of white rats. Based on the results of the experimental research, new data were obtained and the existing ideas about the age-related features of metabolic processes during drinking water with excessive nitrate content were deepened. It was established that the regions of Ternopil region with the largest number of samples in which the nitrate level exceeded the MPC in 2016–2021 were Borshchivskyi, Zalishchytskyi, and Pidvolochyskyi. It was found that the average daily dose of nitrates entering the human body in these areas exceeds the reference level, which indicates the existence of an average risk of harmful non-carcinogenic effects for consumers of this drinking water. The highest average daily dose and hazard ratio were observed in children. It has been proven that the use of drinking water with an excessive concentration of nitrates is manifested by structural and morphological disorganization of hematopoiesis, which is accompanied by changes in the bone marrow and peripheral blood. In the age aspect, more pronounced changes occur in sexually immature rats under the condition of drinking water with a nitrate content of 500 mg/l. A reliable increase in the level of total cholesterol, triglycerides, total protein, catalase, and ceruloplasmin in sexually mature rats compared to sexually immature rats was found when nitrates were supplied with drinking water in the studied concentrations. It was established that nitrates in concentrations of 250.0 and 500.0 mg/l cause reliable multidirectional changes in the relative weight of the liver and blood glucose in rats of experimental groups of both age categories.