Modern Level of Petroleum Products in Water of Lake Baikal and Its Tributaries

Data on the determination of petroleum products in surface and near-bottom water of Lake Baikal and its tributaries by means of express method (fluorometry, 168 samples) on board the research vessel are presented, as well as the data on n-alkanes and polycyclic aromatic hydrocarbons (PAH) obtained under laboratory conditions by means of gas chromatography/mass spectrometry. It was established that the oil product content of surface waters at the deep-sea stations of reference section does not exceed 10 mu g/dm(3), in water depth and in the near-bottom layer 5-7 mu g/dm(3), including n-alkanes - 0.15 mu g/dm(3), PAH (priority pollutants) - 0.012 mu g/dm(3); the concentration of benzo[a]pyrene is up to 10 times below MPC for drinking water (0.005 mu g/dm(3)), total content of six PAH compounds under control in drinking water of EEC is up to 50 times lower than MPCEEC (0.2 mu g/dm(3)). Increased background of oil products reaching 50 mu g/dm(3) (MPC for fishery) was detected at limited regions of intense navigable waterways. Extremal concentrations of oil products (up to 1.3 . 10(4) mu g/dm(3)), n-alkanes (up to 500 mu g/dm(3)), PAH (up to 20 mu g/dm(3)) were discovered in the samples taken from the water surface of the lake in the regions of natural oil shows. With an increase in the distance from oil show boundaries (oil spots on water surface) the concentrations of oil products decrease sharply but exceed the average value for the water area of the lake almost by a factor of two (11 mu g/dm(3)).