Natural radioactivity around a prospected uranium mining area in Finnish Lapland

An environmental survey of natural radionuclides was carried out around the Pahtavuoma uranium occurrence site at Kittilae in Finnish Lapland. The aim of the survey was to determine the background levels of these nuclides in the terrestrial and aquatic ecosystems before changing the natural conditions by mining. All of the samples collected were analyzed for Ra-226 after radiochemical separation. Low Ra-226-content, < 0.02 - 1.9 Bg/kg d.w., was measured in locally produced foodstuffs, reindeer, elk and fish, cloudberry and blueberry; levels were 1.4 - 4.6 Bq/kg d.w. in cowberry. Contents of 0.3 - 5 Bq/kg were found in lichen, beard lichen, hay and fish bones, and higher concentrations in elk and reindeer bones (20 - 62 Bq/kg), aquatic plants Hippuris vulgaris (11 - 90 Bq/kg), and sediments (7 - 130 Bq/kg). The highest Ra-226 concentrations (110 - 3100 Bq/kg) were measured in aquatic mosses (Fontinalis sp). The Rn-222 and Ra-226-concentrations measured in surface and well waters were not higher than the average for Finland. Po-210 and Pb-210 determinations are in process. Dose rate and spectroscopic in situ measurements were performed as well. The results indicate lower environmental activity than the average for Lapland, except at the actual uranium mining site