ON THE RISK ASSESSMENT OF DRINKING WATER CONSUMPTION IN SOME REGIONS OF UKRAINE

Abstract

Evaluation of environmental risk under increasing anthropogenic pressure is an effective tool for managing the state of the environment and serves as a basis for making informed decisions in the field of environmental safety. Therefore, the quantitative assessment of such risks becomes an urgent task and requires careful and balanced consideration, given the significant difference between the concepts of sanitary-hygienic regulation and environmental risk assessment. While the former assumes the existence of a threshold level of hazardous exposure to a specific substance, the latter is based on a non-threshold model that predicts a probable increase in morbidity due to exposure to toxic substances. This article critically reviews the results of quantitative risk assessments of drinking water from the Kherson groundwater deposit and the centralized water supply system of the city of Mykolaiv, as presented in Ukrainian scientific publications. It is shown that the authors employed inappropriate risk assessment formulas when calculating non-carcinogenic risks using a non-threshold approach, leading to incorrect conclusions about catastrophic levels of danger for the population. Actual concentrations of manganese (Mn) and fluoride (F) in drinking groundwater from the Kherson deposit do not exceed the maximum permissible concentrations (MPCs). Therefore, according to the definition of MPC, the presence of these elements in water consumed regularly has virtually no adverse effect on human health. This article provides risk levels for drinking water containing these elements, indicating a “satisfactory” risk level for Mn and an “acceptable” risk level for F. These findings are consistent with the results obtained using the methodology recommended by the United States Environmental Protection Agency (US EPA) for determining the hazard index for Mn and F in drinking groundwater from the Kherson deposit, and for residual chlorine in the drinking water of Mykolaiv. For Mn and F, the hazard index (HQ) is less than 1, indicating that the risk of adverse health effects is absent or negligible. However, the hazard index for residual chlorine (HQ = 5.1) exceeds 1, indicating unsatisfactory environmental safety for the residents of Mykolaiv due to poor drinking water quality.