Pinus sylvestris as a bio-indicator of territory pollution from aluminum smelter emissions

The study demonstrates the efficiency of using Pinus sylvestris L. as a bio-indicator of polluting substances that enter the environment with the emission of a large aluminum smelter. Recent research has demonstrated that pollution from aluminum smelter emissions covers a vast territory. The highest content of polluting elements is registered at a distance of 3 km from the smelter, with maximum concentrations found in the industrial zone (0.5 km from the smelter). The farther from the aluminum smelter, the lower the amount of polluting elements in the needles, although the F level still exceeds the background values at a distance of about 60 km from the source, the levels of Zn, Pb, and Cd up to 50 km, S up to 40 km, and Fe and Cu up to 35 km mostly in north-eastern and south-eastern directions correlating with prevailing atmospheric transfer of the emissions. Pollution with polycyclic aromatic hydrocarbons (PAHs) is also most expressed at a distance of 3 km from the smelter, then it gradually decreases to coincide with background concentrations at a distance of more than 60 km. This is confirmed by changes in overall PAH content and in qualitative and quantitative compositions of individual PAHs. The greatest number of components (17 substances) has been found in samples from the territory of the plant area: phenanthrene, fluoranthene, pyrene, chrysene, acenaphthylene, acenaphthene, anthracene, fluorene, benz[а]anthracene, benz[b]fluoranthene, benz[k]fluoranthene, benz[а]pyrene, benz[е]pyrene, perylene, indeno[1,2,3-c,d]pyrene, benz[g,h,i]perylene, and dibenz[a,h]anthracene. The farther away from the plant, the lower the number of components detected in PAH fraction, mainly due to the fact that the concentrations of most toxic PAHs with five or six aromatic rings (benz[b]fluoranthene, benz[k]fluoranthene, benz[а]pyrene, benz[е]pyrene, perylene, indeno[1,2,3-c,d]pyrene, benz[g,h,i]perylene, dibenz[a,h]anthracene) fall below the method detection limit. High concentrations of benz[а]pyrene and perylene in pine needles at the territories adjacent to the aluminum smelter confirm the technogenic character of forest pollution by PAHs.