Monitoring of Benzo(a)pyrene Pollution of Bottom Sediments of the Lake Baikal in the Sites of Increased Anthropogenic Load over the Period from 2011 to 2021

Abstract— The article summarizes the long-term data on the concentrations of benzo(a)pyrene in bottom sediments of the coastal zone of the lake Baikal in the places of economic activity, obtained by HPLC and fluorimetric detection in 2011‒2021 in the framework of state monitoring. The average concentration of benzo(a)pyrene during the observation period in 2011‒2021 was 2.2 ng/g at the stations of the BAM test site; 0.6 ng/g near the Small Sea; 1.7 ng/g at the site in the front delta of the Selenga river, and 10.7 ng/g at the BPPM site. It was found that the average concentration of benzo(a)pyrene in the samples of bottom sediments, taken from a depth of more than 100 m at the BPPM site was about 1.5‒2 times higher than in the sample taken fron at a depth of less than 100 m. The minimum concentrations of benzo(a)pyrene were found in polydisperse samples with a low organic carbon. High and very high Pearson correlation coefficients between the average concentrations of benzo(a)pyrene and C_org in the bottom sediments of the study sites at the Lake Baikal were obtained. The maximum concentration of benzo(a)pyrene in the organic carbon of bottom sediments was found in the southern part of Baikal, where the average concentration of BaP/g C_org at the BPPM site was almost an order of magnitude higher than at the BAM, MM, and Selenga sites.