Вестник МГТУ, 2026, Т. 29, № 1.

Чуйкина Д. И. и др. Химический состав поверхностных вод в условиях антропогенной нагрузки. Chemical composition of surface water under anthropogenic load (on the example of small reservoirs in the Tomsk region) Daria I. Chuikina, Irina S. Korol*, Natalia A. Mukhortina *Trofmuk Institute o fPetroleum-Gas Geology and Geophysics o f SB RAS, Tomsk Department, Tomsk, Russia; e-mail : irinakorol@yandex.ru, O RCID https://orcid.org/0000-0002-8022-9678 Abstract Assessment of the natural waters' state requires an integrated approach including the determination of a wide range of physico-chemical parameters, on the basis of which specialized indexes and classifications are developed. Traditional analysis methods do not always take into account the effects of a number of pollutants, such as polyaromatic hydrocarbons (PAHs), which can have a significant impact on ecosystem processes and the quality of the aquatic environment. The paper presents the results of studies of small lakes in the Tomsk district (Tomsk region) affected by anthropogenic activity, which are freshwater reservoirs with electrical conductivity values of no more than 0.34 ms/cm, pH values up to 7.2. The content of inorganic macro components (cations and anions) does not exceed the maximum permissible concentrations (MPC), which indicates a satisfactory chemical composition of the water. The content of photopigments in bottom sediments has been analyzed in detail. A wide range of chlorophyll a concentrations from 0.35 to 2.3 ^g/g has been recorded for all the studied samples, which may be due to the heterogeneity of the spatial distribution of phytoplankton and the trophic status of reservoirs. The individual and total content of 13 priority PAHs in surface waters has been studied in detail. Their total concentrations range from 0.37 to 0.54 ^g/l, which indicates the presence of a moderate level of contamination; naphthalene, fluorene, phenanthrene and benz[a]anthracene predominate in the composition, which have the ability to bioaccumulate. Based on the data obtained, the water pollution index (WPI) has been calculated showing that all the lakes studied belong to the category of moderately polluted, approaching the border with polluted reservoirs. Thus, the study has made it possible to assess the impact of unintended anthropogenic impact on the chemical composition of surface waters of small reservoirs in the Tomsk region. Special attention has been paid to the role of polyaromatic hydrocarbons in the formation of the ecological state of water bodies and their contribution to changes in the values of the water pollution index. The results obtained demonstrate the importance of such studies for monitoring and protecting aquatic ecosystems. Chuikina, D. I. et al. 2026. Chemical composition of surface water under anthropogenic load (on the example of small reservoirs in the Tomsk region). Vestnik ofMSTU, 29(1), pp. 75-89. (In Russ.) DOI: https://doi.org/10.21443/1560-9278-2026-29-1-75-89. 76 Article info Received 17.12.2025; received in revised form 20.02.2026; accepted 24.02.2026 Key words: surface water, ionic composition, polyaromatic hydrocarbons, anthropogenic load, water pollution index, hydrochemical indicators, small lakes For citation