Kola Peninsular is one of the most industrially developed regions of the country. Mining enterprises, metallurgical complex and nuclear power engineering objects are operating there. Besides, Kola Peninsular is famous for its pine woods. In the man-made world, it is the pine-tree that indicates to purity of the air; its needles show the environment contamination degree. This surprising property has been used by researchers of Kola Peninsular for several dozen of years for investigation of aerotechnogenic contamination. The main subject of inquiry was the key delinquent of the black, burnt grey waste ground formation in the middle of the peninsular — the Monchegorsk copper-nickel industrial plant “Severonikel”. The picture turned out to be gloomy, yet incomplete.
To make it more vivid, young researchers from the Polar-Alpine Botanical Gardens-Institute (Apatity) suggested a comprehensive investigation scheme. “We have taken not one but three “pipes” at once, says Alexei Kizeev, Ph.D. (Biology). The Kandalaksha aluminium plant is located in the south of the peninsular, the “Severonikel” industrial complex is closer to the north, and the Kola nuclear power plant is between them. It means that besides heavy metals, sulfur, fluorine and aluminium emitted by metallurgical enterprises, researchers can investigate influence of low doses of radio-activity— for the first time along with other components of contamination.”
The two-year pine needles were collected since 2004 through 2007 every month (since July through September) on six grounds. One of the grounds was located not far from the Kola nuclear power plant, one more – not far from the first — near the aluminum plant, and two others — in the environment of the “Severonikel”. The two remaining grounds were located not so close to the enterprises but still in the zone of their influence. It has turned out that nearby the “Severnikel”, pine needles strongly accumulate heavy metals — Ni, Cu, Co, Fe, Pb, as well as sulphur, and as the distance increases their quantity drops exponentially. By the way, in recent years, the Monchegorsk copper-nickel industrial complex has significantly reduced volumes of atmospheric emission due to implementation of new purification technologies. Nearby the enterprise, the wayside has already turned green, probably, the remission process will soon begin with pine-trees. The fluorine and aluminium content in pine needles is certainly high near the aluminium plant, and as the distance increases the content reduces but not so abruptly.
As per the Kola nuclear power plant, it has not justified gloomy expectations of the “green” who believe that nuclear power engineering to be the main world evil. Capacity of the pine needle exposure dose remained within the limits of natural radioactivity in all cases, it did not exceed 15 microroentgen per hour. Specific ?- and ?-activity strongly varied due to different contents of natural and man-made radionuclides. Among them, there were radionuclides from the uranium-238 (226Ra and 214Pb) and thorium-232 (232Th and 228Ac) rows, coming in mainly from the soil, natural 40K, which is contained in all vegetable objects along with ordinary potassium, as well as 7Be of outer space origin. As per man-made radionuclides, 137Cs and 90Sr were found — their accumulation is connected with the natural circulation of fission products, which came into the atmosphere and soil from nuclear weapons tests and due to global environment contamination by emissions from the Chernobyl nuclear power plant. As per the Kola nuclear power plant, its contribution, if any, was very insignificant: the grounds closest to it were not distinguished by any “radiation” indicators.
The researchers have also investigated physiological parameters of pine needles — the length and mass of needles and their biochemical peculiarities. It has turned out that the shortest needles of a small mass belong to pine-trees near the “Severnikel” plant, they also contain most of moisture (this is due to active detoxication). The pine needles collected near the “Severonikel” and Kandalaksha aluminum plants have a high contents of flavonoids — probably this is adjustment to increased oxidizing processes.
Interesting results were obtained at the ground in the Pirenga river area. The samples collected there had increased specific ?- and ?-activity and demonstrated intense accumulation of natural and man-caused radionuclides (even as compared to the ground that is the nearest to the Kola nuclear power plant — the reason can be, for example, rock yield with increased radionuclide contents). Besides, the content of biophil elements (Mn, K, P, N, Mg, Al, F) also increased there, and the heavy metal content decreased. The fact that the elements are accumulated selectively has been confirmed by investigation of their contents in the snow collected in the same area. Biochemical changes in these pine needles, such as increased water content, decreased chlorophyll and carotinoid content, and changes in correlation between pigments, testified to reduced physiological age of the pine-tree. On the other hand, structural changes in pine needle chloroplasts on this ground are probably adaptation to increased photosynthesis intensity. It is quite possible that weak radiation influence stimulated the pine-tree adaptive capabilities as regards to heavy metal contamination.