Više biljke kao biomonitori radionuklida u urbanom vazduhu

Abstract

U radu su prikazani rezultati analize dve vrste listopadnog drveća, lipe (Tilia tomentosa L. i Tilia cordata Mill.) i kestena (Aesculus hippocastanum L.), kao mogućih biomonitora radionuklida 210Pb i 7Be u vazduhu. Studija je sprovedena tokom 2002. – 2009. godine, u tri parka na području Beograda. Aktivnosti 210Pb i 7Be u uzorcima lišća i aerosola su odreñene na HPGe detektoru standardnom metodom spektrometrije gama zračenja. Značajne razlike u aktivnostima izmeñu mernih lokacija i vrsta drveća nisu uočene, odakle se može zaključiti da je uticaj mikro klime, nivoa zagañenja i fizioloških karakteristika tipova drveća na akumulaciju radionuklida u lišću zanemarljiv. Aktivnosti radionuklida u lišću i u aerosolima su korelisane koristeći linearne Pirsonove koeficijente. Kako lišće lipe daje informaciju o istoriji aktivnosti 210Pb u vazduhu, ono se može koristiti kao biomonitor ovog radionuklida. Za aktivnosti 7Be u lišću i u vazduhu nisu dobijene značajne pozitivne korelacije.

Two deciduous tree genera, linden (Tilia tomentosa L. and Tilia cordata Mill.) and chestnut (Aesculus hippocastanum L.), are analysed as biomonitors of 210Pb and 7Be in air. In a multiyear study (2002 – 2009), conducted in three city parks in Belgrade, the content of 210Pb and 7Be in samples of leaves of linden and chestnut trees, and aerosols was determined on an HPGe detector by standard gamma spectrometry. The differences seen in the radionuclides’ activities across the measurement sites and between the tree genera are not significant, suggesting that the micro climate, level of air pollution and physiological characteristics of the trees have a negligible effect on the radionuclides’ activities in leaves. Linear Pearson’s correlation coefficients are used to correlate the 210Pb and 7Be activities in aerosols and in leaves. The results show that linden could be used as a 210Pb biomonitor which provides information on the recent history of exposure. No large positive correlation is found for the 7Be activities in leaves and aerosols, indicating that higher plants are not a suitable biomonitor for this radionuclide.