Health risk assessment of the population of the Republic of Buryatia associated with increased nitrate and nitrite intake

Abstract

Aim. Carry out a hygienic assessment of the health risk levels associated with drinking water with high nitrate and nitrite content in the rural territories of the Republic of Buryatia. Methods. The assessment of the content of nitrates and nitrites in drinking water in comparison with the maximum permissible concentrations (MPC) in the period 2010-2019. Based on the application of the risk assessment methodology, non-carcinogenic risk (HQ) for adult and child populations of priority territories is calculated. Results. On the territory of the Republic of Buryatia, according to the largest content of nitrates in the drinking water of a centralized cold water supply system, 2 priority territories were identified: Mukhorshibir and Tarbagatai districts. The maximum nitrate concentrations reached 4,52MPC and 4.11MPC, respectively, which is 1.71 and 1.45 times higher than in the previous 5-year period. A similar situation was observed in the non-centralized water supply system in these areas, including in the Mukhorshibirsky district 1.88 times (4.98MPC), Tarbagatai 2.53 times (3.41MPC). Conclusions. The unacceptable level of non-carcinogenic risk due to nitrate contamination of drinking water at the level of the average centile trend (Me) is established for the adult and child population provided with centralized water supply in the Tarbagatai region. The HQ exceeds the acceptable level for children consuming decentralized drinking water in the Mukhorshibir district. The risk levels for children and adults due to the oral intake of nitrites with drinking water of centralized and non-centralized water supply were not dangerous (HQ1).

Some Methodological Approaches to Assessing Health Risks Related to Potable Water Quality in Centralized Water Supply Systems

“…При усреднении концентраций веществ для оценки риска большинство авторов придерживаются Руководства и находят среднеарифметическое значение либо верхний предел 95 % ДИ. Также авторы, которые указывают на статистически отличные от нормального распределения, используют значения медианы, а для аггравированного (преувеличенного) сценария используют значения 90-го или 95-го процентиля [14,28,29]. В методических рекомендациях по организации мониторинга качества питьевой воды (МР 2.1.4.0176-20) аналогично предлагается использование медианы при анализе малого количества данных.…”