Measured 234,238U and Fallout 239,240Pu in Human Bone Ash from Nepal and Australia

Abstract

Human bone samples from Nepal and Australia were analyzed for isotopic uranium and fallout plutonium. The Nepalese samples were obtained for a 3-yr period (197678) while the Australian samples are representative of a single year (1977). The surface air plutonium concentrations for the latitude bands of these countries were either measured and/or estimated from 1954 through 1978. With the plutonium air concentrations and age-dependent breathing rates as input data, the measured human bone results were compared with skeletal estimates derived from the ICRP Task Group Inhalation Model, and the agreement was found to be reasonably good.The measured isotopic uranium concentrations in these samples provide a benchmark against which to assess fallout plutonium based upon a comparison of the skeletal a radiation dose from a natural actinide to these populations.

Environmental radiation – an important concern in the Himalayas (Nepal)

“…Cesium-137 concentrations in Nepalese samples (93-417 Bq/kg) are comparable to those measured in Scandinavia (152-3466 Bq/kg), Italy (118-11,084 Bq/kg) and Antarctica (47-134 Bq/kg) (Triulzi et al, 1996). Other studies have also confirmed the contamination of the Himalayan region with cesium-137 (Balerna et al, 2003), as well as with strontium-90 and plutonium-239/240 (Fisenne et al, 1983). Human breast milk from Nepal has shown elevated levels of cesium-137 even 10 years after the Chernobyl accident (Lechner et al, 1997).…”

“…As a result of global fallout, radioactive pollution is undoubtedly present in Nepal. Fisenne et al (1983) estimated cumulative plutonium doses received by bone cells among the dead human samples collected from Nepal and Australia, and the results indicate that there was higher plutonium fallout in Nepal than in Australia. The 1986 Chernobyl nuclear power plant accident in Ukraine further increased the environmental radioactivity into the global environment, with most of the fallout being noticed in Russia, Belarus, Ukraine, Scandinavia and other parts of Europe.…”

“…cesium-137 and plutonium) on the glacier surface (alpine cryoconites) can have remarkably high levels, surpassing those in other environmental media (Tieber et al, 2009). The cesium and plutonium radioactive deposits in the Himalayan region (Fisenne et al, 1983;Triulzi et al, 1996;Balerna et al, 2003) are therefore likely to become remobilized, suggesting that these radionuclides could be potential tracers to understand glacier activity in the Himalayan ecosystem in Nepal, a matter of scientific interest for radioecologists and environmentalists internationally.…”