Relevance. The protected Baikal territories are becoming more involved in the tourism industry every year, which does not contribute to the preservation of their unique natural qualities. For competent legal regulation of anthropogenic pressure and the formation of ecological culture, information is needed about the ability of the natural system to self-regulate and self-repair and the pace of this process. Aim. To compare the ecobarrier abilities of the sandy sediments of the Tagheran steppe and Olkhon Island in relation to aggressive effects. Methods. The composition of the sand samples was determined by powder diffraction on a DRON-3.0 X-ray diffractometer, and the concentrations of rock-forming oxides were determined on an S8 TIGER wave dispersion spectrometer. Sorption capacity under static and dynamic conditions of contact of sands with media simulating domestic wastewater, the surface tension or electrical conductivity of solutions was measured. The interpretation of the results of colloidal chemical studies was performed using Excel. Results and conclusions. Despite the geographical proximity of the selection sites and the granulometric similarity of the sands, their eco-barrier abilities differ significantly. The sands exhibit different activity in relation to solutions of individual surfactants, represented by anion-active sodium oleate and sodium 12/14/16-carbon organosols, as well as to synthetic detergents. In all cases, it turns out that washing the sands does not lead to complete purification. It is shown that the sorption properties of sands depend on their mineral composition, samples of Olkhon sand retain up to 70% of detergents, and Tagheran sand retains up to 50%. The island sands are rich in quartz and feldspar (97.5%) and have a high degree of pollution retention. At the same time, they are characterized by more complete purification by washing, which in natural conditions corresponds to the accumulation of pollutants in the underlying soil layers, the biota of which is under threat. The peculiarities of the mineral composition of the sands of the Tajeran steppe are manifested in less surface activity. The danger of the presence of surfactants in sand layers of this composition is associated with their ability to act as hardness reducers, contributing to the effects of disintegration. The results indicate that, under conditions of planned anthropogenic load, sand deposits can be considered as indicators of the state of the soil cover during continuous monitoring.