<sup>137</sup>Cs in the Population of Northern Sweden

Abstract

Whole-body content of 137Cs has been measured in both 1991 and 1992 in the population of northern Sweden, with a special interest taken in the Saami population. Measurements were performed in three areas with different deposition levels, using a whole-body counter installed in a mobile container. In this way the expected high refusal frequency caused by the large distances in this part of Sweden could be reduced. Two groups of individuals were randomly chosen, one group representing the total population of the area, and the other the members of the Saami communities. In order to investigate whether 15 year old students could be regarded as a representative sample of the total population, measurements of whole-body content and urine samples were performed on school classes in two of the areas. The average whole-body content of 137Cs in the general population varied between 1.1 and 2.0 kBq, and for the Saami population between 3.4 and 25 kBq, dependent on deposition level. The ratios between whole-body content and deposition found in these measurements were consistent with earlier studies of 137Cs from Chernobyl in other areas of Sweden; however, previously published data based on measurements of 137Cs from nuclear weapons fallout, shows a 20-40 times higher ratio. This may be an effect of the different behaviour in the environment of caesium from Chernobyl compared with caesium from nuclear weapons fallout, or a result of effective countermeasures.