The fate of plutonium, 241 Am, 90 Sr and 137 Cs in the Antarctic ecosystem

• Published in: Antarctic science 2000-06, Vol.12 (2), p.141-148
• Main Authors: Jia, Guogang, Triulzi, C., Marzano, F. Nonnis, Belli, M., Vaghi, M.
• Format: Article
• Language: English
• ISSN: 0954-1020; 1365-2079
• DOI: 10.1017/S0954102000000183

A radioecological survey around Terra Nova Bay showed that 239 + 240 Pu, 238 Pu, 241 Am, 90 Sr and 137 Cs activities were detectable in nearly all the samples. The 239 + 240 Pu and 241 Am concentrations in seawater were slightly lower than those in the northern Pacific Ocean. The activity level of 239 + 240 Pu, 241 Am and 137 Cs in Antarctic sediments (Ross Sea) was c . 5–20 times lower than in northern Adriatic sediments (Mediterranean Sea), but the 238 Pu activities were relatively high. The 90 Sr concentrations in all the sediment samples from both the Ross and Adriatic seas tended to be low which might be due to an easier exchange of 90 Sr in seawater. On the other hand, high concentrations were detected in Antarctic mosses, lichens and algae and their activity levels are comparable to those in central Italy. The radionuclide ratio analyses show that the major part of 239 + 240 Pu, 241 Am, 90 Sr and 137 Cs is the result of nuclear weapon tests. A higher 241 Am/ 239 + 240 Pu ratio might be due to the fallout of earlier atmospheric nuclear tests. The 238 Pu 239 + 240 Pu ratio in the Antarctic matrices is about seven times higher than in the Northern Hemisphere and this could suggest that the major part of 238 Pu originated from the SNAP-9A satellite accident.