Radioactivity in the Atmosphere

Abstract

A short review is made on atmospheric radionuclides with emphasis on their activity concentrations in the troposphere, mostly for surface air over Europe. Discussed are those species which have activity concentrations above about 1 mBq/m 3 . For this atmospheric layer highest average activity concentrations (> 1 Bq/m 3 ) have i) 222 Rn ("radon") and its short-lived decay products, (ii) 220 Rn ("thoron"), however, only for the lowest meter above ground, and iii) a5 Kr. In the range 1 mBq/m 1 to 1 Bq/m 3 are Τ(Ή), ,4 C, 37 Ar and 7 Be as well as the "thoron" decay product 212 Pb. Average activity concentrations slightly below 1 mBq/m 3 has 210 Pb, the only long-lived decay product of "radon". The sources of these radionuclides are discussed. Not included in this review are radionuclides contained in the atmosphere at very low activity concentrations or from single emissions such as e.g. from the Tschernobyl accident in 1986.

Beryllium-7 Measurements in the Houston and Phoenix Urban Areas: An Estimation of Upper Atmospheric Ozone Contributions

“…Approximately 66% of the total 7 Be is produced in the stratosphere, and ϳ33% is produced in the upper troposphere, 11,15 with a peak production at ϳ15 km. 12,15 7 Be is a ␥ emitter with a 53.29-day half-life, and, once formed, it rapidly becomes attached to submicron aerosol surfaces in the upper atmosphere.…”

Air Radioactivity Monitoring in Serbia

“…On global scale air radioactivity monitoring provides important data for comparing environmental impact of radioactivity from anthropogenic sources to natural ones and for studying global atmospheric processes (Baeza et al, 1996;Gaggelar, 1995;Gustafson et al, 1981;Arimoto et al, 1999;.…”

“…Most commonly radionuclides monitored in ground level air are cosmogenic 7 Be, natural 210 Pb and anthropogenic 137 Cs. Berillium-7 (half life 53.28 days) is produced by cosmic rays in spallation processes with light elements (N,O,C) in the upper troposphere and lower stratosphere and its annual mean concentrations are good indicator of the changes in the atmospheric production rate due to cosmic ray intensity and are correlated to stratosphere-to-troposphere exchange processes (Gaggelar, 1995;Gaffney et al, 2004). Concentrations of 7 Be in air at midlatitudes exhibit maxima in spring/summers periods attributed to seasonal thinning of tropopause that allows stratospheric masses rich with 7 Be to enter the troposphere (Agelaio et al, 1984;Bettoli et al, 1998;Cannizzaro et al, 1995;Hirose et al, 2004;Ioannidou & Papastefanou, 1997;Todorovic, 1997).…”

“…Concentration of 7 Be in air is effected by air exchange between stratosphere and troposphere, vertical mixing within the troposphere and the washout effects (Todorovic, 1997;Gerasopoulos et al, 2003). 210 Pb (half life 22.3 years) is produced in the decay of 238 U into gaseous 222 Rn (half life 3.8 days) that escapes from soils into the atmosphere where one of its short lived daughters ( 218 Po) decays into 210 Pb (Gaggelar, 1995;Gaffney et al, 2004;Groundel & Postendourfen, 2004;Todorovic et al, 2000). In small amounts radon and thus 210 Pb are produced in coal combustion processes and nuclear explosions (Todorovic et al, 2007).…”

Airborne Radioactivity in Hot Lab of Nuclear Medicine

“…One can distinguish between three different origins of natural radionuclides: primordial, decay products and cosmogenic. Primordial cosmogenic or anthropogenic radionuclides present in the ambient air are useful tracers for studying physical and health-related processes in the atmosphere [1]. Primordial radionuclides, like e.g.…”