Background radiation dose-rates to non-human biota in a high mountain habitat in Norway

Abstract

Abstract. Determination of background radiation dose-rates is important in the process of assessing risks to the environment from exposure to human activities both in terms of deriving the incremental dose-rate and as a point of reference for evaluating the significance of the exposure level. A consideration of the available literature on naturally occurring radionuclides in wild plants and animals quickly illustrates a paucity of data coverage in numerous cases. Most notable is the lack of comprehensive information for the important dose-forming radionuclides such as 210 Po and 210 Pb. In order to collate data concerning these radioisotopes for components of the ecosystem, field work was conducted in a semi-natural, mountainous location in central Norway. Preliminary (since no correction was made for ingrowth from 210 Pb) whole-body activity concentrations of 210 Po in 2 species of small mammal were commensurate with activity concentrations reported for reindeer muscle sampled at proximate locations, falling at a level of some 10s of Bq kg −1 by fresh weight. Statistical analyses of the data showed that bank vole and shrew 210 Po data constitute different populations with different mean ranks. Unweighted dose-rates attributable to the presence of internally distributed 210 Po were calculated to be 0.07 Gy h −1 for Bank vole.

Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

“…The common shrew feeds on most terrestrial insects, but will also take worms, slugs and snails. The effect of diet was hypothesized to be of primary importance from the earlier work on this dataset by Brown et al (2009), and the effect of this and other factors on the transfer of 210 Po is considered in more detail below. The 210 Po activity concentrations for the whole body of the bank vole and shrew were similar in magnitude to activity concentrations determined for the muscle of reindeer, sampled at a site about 75 km distant at Vågå in Norway.…”

Detection of Polonium-210 in Environmental, Biological and Food Samples: A Review

“…Szarlowicz et al [89] reported that for smaller masses (0.1-0.2 g) of sediment samples, microwave digestion using concentrated HNO 3 + HCl gave acceptable recoveries of polonium and did not require the use of HF, effectively reducing both processing time and cost. Although the microwave digestion technique is a promising method, it is only capable of rapid and accurate detection of very small amounts of organic matter (typically 0.5 g dry, 2-3 g wet), so for larger masses of samples (20-25 g, wet weight), it may be necessary to split them into multiple digestion vessels to obtain the sensitivity required to measure low levels of 210 Po [90].…”