Current State of the Natural Environment of the Southwestern Shore of Lake Baikal (Slyudyansky District)

This article presents the results of research carried out on the basis of field and desktop analytical studies conducted in 2024 on the southwestern shore of Lake Baikal. Samples of snow, surface waters, soil, and vegetation were collected at key sites. Geochemical parameters of the main components of the natural environment near sedimentation ponds, industrial site of the Baikal Pulp and Paper Mill (BPPM), and coastal settlements with a high recreational load are presented. It is found that the content of heavy and alkaline earth metals, $${\text{SO}}_{4}^{{2 - }},$$ $${\text{NO}}_{3}^{ - },$$ $${\text{NH}}_{4}^{ + },$$ and $${\text{PO}}_{4}^{{3 - }}$$ ions in snow near the village of Kultuk and the towns of Slyudyanka and Baykalsk exceed background values; concentrations of $${\text{NH}}_{4}^{ + },$$ Pb, and petroleum products in snow water exceed the MAC and APC. The main sources of pollution are construction and road enterprises, thermal power plants, boiler houses, railway and automobile transport, waste landfills, and sedimentation ponds. The sources of surface water pollution with phosphates and ammonium are housing and communal service facilities. Soil pollution with heavy metals has been detected in the recreational and industrial zones located on the lake shore. Regional features of correlations between the concentrations of macro- and microelements in soils and the hydrogen index, organic carbon content, and physical clay fraction have been identified, which indicates the presence of biogeochemical barriers where they accumulate in concentrations above the MAC. The biological absorption coefficient shows a dependence on acid–alkali conditions. The coefficient of migration of microelements into surface waters from soils is low. However, in the coastal waters of the lake, concentrations of heavy metals exceed the MAC for fishery waters due to their large amount in soils. Macroelements have a higher migration intensity. It has been established that the concentrations of fluorides, phosphates, ammonium, nitrate, and nitrite nitrogen exceed the background levels in the waters of the sedimentation pond; the estuary zones of the Khara-Murino, Kharlakta, and Utulik rivers; and the coastal waters of the lake near Baykalsk, Utulik, Slyudyanka, and Kultuk.