Phthalates in Bottom Sediments of Lakes on the Eastern Coast of Baikal

Phthalates are ones of the most common pollutants, the concentrations of which in the environment in the near future will only grow according to predictions by scientists. High concentrations of these substances pose a serious threat to water bodies, especially for lake ecosystems, which are characterized by slow water exchange and which accumulate pollutants faster, thereby reflecting the anthropogenic load and environmental changes. This work presents for the first time the results of determining the phthalate contents in the bottom sediments of Arangatui, Bormashovoe, Dukhovoe, Kotokel, and Shchuchye lakes. The total content of six phthalates varied from 51 to 2222 μg/kg dry matter, and the highest concentrations were recorded for the central stations. The distribution profile of phthalates in the bottom sediments of these lakes is quite similar; DBP (average content of 213 μg/kg) and DEHP (189 μg/kg) dominated. It is noted that the accumulation of the studied substances occurs mainly in silty sediments, which is indicated by medium and high positive correlations between phthalates, the particle size distribution, and the content of organic carbon and heavy metals. The high levels of individual phthalates in the bottom sediments of the studied lakes indicate the need to study in detail the sources and distribution mechanisms in the system of “water–bottom sediments.”