Toxicity assessment of bottom sediments in watercourses in Selenga River basin on the territory of Mongolia

Bioassay methods are used to assess the toxicity of bottom sediments in the main watercourses of the Selenga River basin and Lake Orog in Mongolia. Toxic bottom sediments are found in a brook in the region of the Erdenet Mining and Concentration Complex, as well as in the Eroo and Bukhlyn rivers, which experience the effect of intense gold mining. The conclusion is drawn that the Selenga River water flowing from the territory of Mongolia cannot directly affect the quality of water in Lake Baikal.