“…For example, in three samples from November 2008 Tinker et al observed Xe-135/Xe-133 ratios ranging from 0.004 to 0.072 at the stack of the ANSTO radiopharmaceutical facility in Sydney, and ten samples measured in Melbourne-approximately 500 km away-over the following months had a maximum Xe-135/Xe-133 ratio of 0.16 and a maximum Xe-135 activity of 0.33±0.15 mBq/m 3 . 29 Seven of the 10 measurements were upper limits. Similar findings are reported by Saey et al for the Nuclear Technology Products Radioisotopes (Pty) MIPF in Pelindaba, South Africa and the Institut des Radioelements MIPF in Fleurus, Belgium.…”