Accumulation of polyarenes in higher plants of hummock peatlands in the southern and northern tundra

We studied the content of polycyclic aromatic hydrocarbons (PAHs) in plants of the background hummock peatlands in the southern (Vorkuta district, Komi Republic) and northern (Nenets Autonomous District) tundra. PAHs in plants were determined by high-performance liquid chromatography. We used ASE-350 Accelerated Solvent Extraction System (Dionex Corporation, USA) to extract PAHs from samples. Totally, 11 individual PAH structures were found in the plant samples studied. Low molecular weight PAHs were prevalent in all studied plants. The highest content of PAHs was found in plants at southern tundra (28 km northwest of the Vorgashor village); the lowest - at site in northern tundra (100 km northwest of the Vorgashor village). In the plants of the southern tundra, an increased content of 2-3-ring polyarenes was detected, that was possibly caused by long-distance transport from the Vorkuta industrial agglomeration. In plants from the Barents Sea coast, we revealed an increase in mass fraction of high molecular PAHs of biopedogenic origin, which were accumulated by plants from the peat waters. For sedges and cotton grasses, an increased content of benz[k]fluoranthene and benz[a]pyrene has been detected. This fact may be associated with the active root uptake of polyarenes characteristic of herbaceous plants. The results of the cluster analysis showed that the polyarenes content of the plants was determined both by their species composition and by the geographical location of the study sites. The clustering of different plant species from different sites indicates the background concentrations of PAHs, which are maintained by plants under natural conditions without anthropogenic impact. Based on these studies, background concentrations of PAHs in different species of peatland plants have been proposed, which can be used for monitoring PAHs pollution in mire ecosystems of the north.