Risk analysis of water-nitrate methemoglobinemia in the hygienic monitoring system of decentralized water supply sources

Abstract

In the context of numerous water and environmental challenges, nitrate contamination of well water stands out as a particularly urgent concern, posing a significant risk for the development of water-nitrate methemoglobinemia – especially in young children. This study aimed to conduct a comprehensive risk assessment of this condition associated with elevated nitrate levels in decentralized water supply sources in the Kharkiv region and to develop a scientifically grounded set of preventive measures. Materials and methods. A retrospective analysis was conducted on laboratory monitoring data of well and spring water quality in the Kharkiv region, alongside an age- and sex-based statistical analysis of methemoglobinemia incidence. Results. A systemic issue of nitrate contamination in well water was identified, with the proportion of samples exceeding permissible nitrate levels ranging from 37.7% to 47.2%, and an average non-compliance rate of 42.2 ± 3.22%. Additionally, an age- and sex-based analysis of water-nitrate methemoglobinemia cases was conducted. It was found that the concentration of nitrates in the water that caused the poisoning ranged from 51 to 530 mg/dm³, with an average value of 287.3±146.14 mg/dm³. The maximum concentration of cases occurred in the first year of life (70 %), of which 25 % were recorded in the group of infants under 1 month of age. Conclusions. This article highlights the ongoing issue of nitrate contamination in decentralized water supply sources in the Kharkiv region, which poses a continuous risk of water-nitrate methemoglobinemia, particularly among young children