“…In addition, the only sink for radioxenon in the atmosphere is its radioactive decay, hence, the atmospheric residence time is equal to the mean radioactive lifetime, thus allowing for long-range transport in the atmosphere. Also, the typical atmospheric background level is low, e.g., in the order of 1 mBq/m 3 in Central Europe, Japan and US (DE GEER, 1996b, WEISS et al, 1997BOWYER et al, 1997BOWYER et al, , 2002IGARASHI et al, 2000), due to lack of significant natural sources and due to the relatively short half-lives of the radioxenon isotopes. In contrast to radioxenon, the high atmospheric background of 85 Kr, currently approximately 1.5 Bq/m 3 in the Northern Hemisphere (HIROTA et al, 2004) with a high temporal and geographical variability (WEISS et al, 1992;WINGER et al, 2005), makes the atmospheric concentration of this isotope relatively insensitive to emissions of nuclear tests.…”