Accumulation of pоlyarenes in soils and shrubs of Betula nana in the southern tundra

The studies of polyarenes content in Betula nana shrub and organogenic horizon of tundra surface gley soil were performed at control site 6 km from the Khanovey railway station and at a distance of 0,5; 1 and 1,5 km from the “Vorkutinskaya” coal mine. It was found that the polyarenes content in Betula nаnа in the polluted areas exceeded the background values 2 times and decreased slightly with the distance from the mine. The greatest frequency of exceeding the background values were found for chrysene and heavy polyarenes. The changes in the content of polyarenes in Betula nana, depending on the distance from the mine, were statistically insignificant. The content of polyarenes in soils of contaminated sites exceeded the background values 7-8 times and decreased slightly with the distance from the source of contamination. It is shown that polyarenes, including heavy ones, in tundra conditions can migrate to a distance of more than 1,5 km. It was revealed that the contribution of surface contamination to the total polyarene content in the plant for all studied sites was approximately the same and amounted to about 20%. Thus, the contribution of different polyarenes structures in the content of polyarenes on the surface of the shrub changed, that depended mainly on their mass. The obtained results indicate the active penetration, mainly of light polyarenes, in the leaves, branches and bark of Betula nаnа at a high level of pollution. At a distance of 1,5 km from the mine, the transport of polyarenes to the surface decreased which led to their lower accumulation. Penetration of polyarenes to the stems of Betula nаnа was low. Polyarenes concentrated on the roots surface that complicated their transport to the terrestrial part of the plant. It is established that at the control site and the sites located at a distance of 1 and 1,5 km from the mine, polyarenes were of petrogenic origin; at a distance of 0,5 km from the mine an additional contribution of pyrogenic polyarenes was revealed due to the proximity of the auto road. Owing to the wide prevalence and the ability to accumulate polyarenes from the environment, Betula nana can be used as an indicator species characterizing the degree of contamination of the territory with polyarenes. When investigating the recent contamination, the leaves of the plant can be used, to analyze the long-term impact it is better to use the bark of Betula nаnа.