Hygienic Assessment of Surface and Groundwater Quality in the Zabaykalsky Krai

Abstract

Introduction. The supply of high quality potable water to the population living within the geochemical provinces remains an important problem since the imbalance of chemical elements is a risk factor for various diseases and syndromes. The purpose of the study was to analyze the quality of surface and groundwater related to the geochemical characteristics of the region and to assess public health risks. Materials and methods. Water quality was analyzed in the areas of the Zabaykalsky Krai characterized by the presence of geochemical anomalies. Non-carcinogenic risk assessment of combined exposure to multiple chemicals in drinking water was carried out in accordance with the requirements of R 2.1.10.1920–04. Results. We established the excess of maximum permissible concentrations for such elements as iron (1.1–5.1 MPC), fluorides (1.1–2 MPC), nitrates (2.2 MPC), manganese (5.1 MPC), zinc (2.5–4.6 MPC), and cadmium (1.3–1.5 MPC). Higher than acceptable values of non-carcinogenic hazard quotients were attributed to the effects of nitrites (HQ = 1.5) and arsenic (HQ = 3.4) on the child population in the Kirinsky district. The total hazard index (THI) exceeded the permissible one for children in the Kyrinsky (5.05), Borzinsky (1.92), Chitinsky (1.19), and Tungokochensky (1.24) districts, the urban-type settlements of Zabaykalsk (2.07) and Priargunsk (1.62), and the towns of Petrovsk-Zabaykalsky (1.1) and Chita (1.87). Arsenic, fluorine, iron, and nitrites in water contributed the most to the risk level. Conclusions. The priority water pollutants included heavy metals, nitrites, arsenic, manganese, iron salts, and fluorides due to local natural geochemical features and industrial pollution. The assessment of the total non-carcinogenic risk based on hazard quotients showed that the children were at higher risk for toxic effects of those chemicals on the immune system, teeth, bone tissue, cardiovascular system, gastrointestinal tract, skin, reproductive, respiratory, and hematopoietic systems, liver, kidney, central nervous and musculoskeletal systems.