Polycyclic Aromatic Hydrocarbons in the Snow Cover of the Baikal Region and the Baikal Lake Basin

Abstract

The purpose is a geoecological assessment of polycyclic aromatic hydrocarbons (PAHs) in the snow cover of the Baikal region and the Baikal Lake. The research covered the most populated southwestern and central territories of the Irkutsk Region (Baikal Region) and the southeastern part of the Baikal Lake coast and the South Baikal water area. GARMIN-e-Trex GPS satellite navigation receiver was used to identify sampling stations. Materials and methods. Snow cover samples were taken in 2019-2020, before active snowmelt – at the end of February, near sources of pollutant emissions – cities, and in the fi rst ten days of March in areas remote from sources of anthropogenic impact. PAHs concentrations were determined in snowmelt water by the chromato-mass spectrometric method. Results and discussion. The results showed the spatial heterogeneity of PAHs inputs in the Baikal region and the Baikal Lake. The composition and concentrations of PAHs diff er in territorial coverage. Up to 14 PAHs have been identifi ed near anthropogenic emission sources. The total concentrations of PAHs range from insignifi cant – 0.353 mg/dm3 (Zima) to anomalously high – 38.00 mg/dm3 in the territory adjacent to the Irkutsk aluminum smelter (IrkAZ, Shelekhov town). Also, on the territory near IrkAZ, abnormally high concentrations of benzo(a)pyrene were found, The levels of pollution of the snow cover with PAHs in the territories located near the sources of emissions and more remote have been established. Also on the territory near IrkAZ anomalously high concentrations of benz(a)pyrene were detected, 231.5 times higher than background values. Conclusions. The obtained research results allowed to carry out geo-ecological assessment of PAH-polluted territories. Maximum and minimum concentrations of PAHs were identifi ed by territorial coverage.