Content of persistent organic pollutants in the estuaries of the Selenga, Barguzin and Upper Angara rivers: the main tributaries of Lake Baikal
G.S. SHIRAPOVA, V.V. TARASKIN, E.Ts. PINTAEVA, L.D. RADNAEVA, S.V. ZHIGZHITZHAPOVA, Ts.Zh. BAZARZHAPOV, E.P. NIKITINA, V.S. BATOMUNKUEV, A.K. TULOKHONOV
Baikal Institute of Nature Management, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, Russia
Keywords: gas chromatography method with tandem mass spectrometry, chromatographic profiles, organochlorine pesticides, polychlorinated biphenyls, polyaromatic hydrocarbons, sources of input
Abstract
The estuaries of the rivers are the most vulnerable objects of the lake system, which first of all respond to natural and anthropogenic changes of the river flow and lake level. Results from studying the content of persistent organic pollutants in the estuaries of the Selenga, Barguzin and Upper Angara rivers are presented. The content and profiles of organochlorine pesticides, polychlorinated biphenyls and polyaromatic hydrocarbons were determined in the natural water samples taken during the winter low-water period of 2022. The analysis of the data obtained by gas chromatography with tandem mass spectrometry in the mode of multiple reaction monitoring established the regularities of distribution and pathways of entry of persistent organic pollutants into the main tributaries of Lake Baikal. It was found that the pollution of waters of the main tributaries of the lake by organochlorine pesticides is not high, and the content of polychlorinated biphenyls is “trace” in nature and does not exceed the detection limits. Analysis of polyaromatic hydrocarbons origin in the estuaries is important because, apart from anthropogenic sources, there are also their natural sources. In this connection, we analyzed the ratios of concentrations of individual polyaromatic hydrocarbons, which are markers of the sources of their entry into the environment. Polyaromatic hydrocarbons in the natural water of the estuarine zones of the main tributaries of Lake Baikal have a mixed genesis (pyrogenic and petrogenic), but most of them are of pyrogenic origin. Data obtained for the qualitative and quantitative composition of persistent organic pollutants can be used for regional ecological-geochemical and ecological-hygienic assessments of the natural environment, identification of sources of anthropogenic impact on the natural environment and environmental risk assessment.
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