Abstract
The radionuclide composition of the atmospheric precipitations (rain and snow) fell out on the territory of the South of the Western Siberia in 2016-2017 was studied. It is shown that, the maximum of deposition of 7Be and 210Pb were observed in a foothill zone (618 and 171 Bq/m2), the minimum in the Alpine zone (104 and 27 Bq/m2), for the forest-steppe zone these values are 237-340 Bq/m2 and 73-93 Bq/m2. Deposition density of 137Cs in comparison with 210Pb and 7Be is small and does not exceed 1 Bq/m2. Average values of total specific activities of 210Pb and 7Be in rain waters are 242 and 2434 mBq/l, in the snowmelt 506 and 1611 mBq/l. 7Be/210Pb activity ratio in rain waters more than three times higher, than in snowmelt: 10,1 to 3,2. The highest values of 7Be/210Pb activity ratios are observed in the finest fraction (<0.45 µm) of the suspended matter: 19 in rain and 10 in snowmelt waters.
Highlights
Radioactive isotopes of natural origin 7Be and 210Pb in significant amounts deposit on the Earth's surface from the atmosphere
Just after production 7Be, 222Rn atoms and its decay products are electrically charged. They attach to aerosols and dust particles and deposit on the Earth's surface with "dry" fallouts and "wet" atmospheric precipitations [3-11]. 7Be and 210Pbatm are often used as indicators of various natural processes, including, geochronological modeling of modern sedimentation processes, study of aerosol transfer in the atmosphere, atmospheric circulation models and meteorological dynamics, etc. [12-29] According to some estimates [30] more than 90% of 7Be and 210Pbatm are delivered to the Earth's surface through "wet" atmosphere precipitations
There are no reliable data about deposition of 210Pb and 7Be with atmospheric precipitations in such extensive region as the Western Siberia
Summary
Radioactive isotopes of natural origin 7Be and 210Pb in significant amounts deposit on the Earth's surface from the atmosphere. They attach to aerosols and dust particles and deposit on the Earth's surface with "dry" (dust, aerosols) fallouts and "wet" (rain, snow) atmospheric precipitations [3-11].
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