Abstract The accident in 1986 at the nuclear power station in Chernobyl, Ukraine, dispersed radioactive Cesium over large areas of Europe. The half life of 137Cs is 30 years and this radionuclide also behaves like potassium, which means that it can easily be taken up by the vegetation or be adsorbed in to the structure of clays, principally illitic clays. When radioCesium decays ionizing radiation is emitted, which is harmful to humans that are exposed, either directly or indirectly through food intake. It is there-fore important to know what happens to the Cesium that is dispersed into the environ-ment. In this project a simulation model was constructed to simulate the adsorption and transport of radioCesium in the soil and plant uptake.

24 years have passed since the Chernobyl accident when radionuclides were spread over largeareas of Europe, including the Scandinavian countries. Today, measurable activities of 137Csare still observed in many Swedish ecosystems.Ants (belonging to the order Hymenoptera) are social insects which collect organic materialfrom a large area around their nests. This study focuses on the 137Cs activity in ant nests andthe Cesium accumulation in these nests. The aims were (1) to estimate the 137Cs fall-out in1986, (2) estimate the radiation exposure of ants and (3) find how 137Cs is distributed in an anthill. Seven ant hills (occupied by the species Formica polyctena) were studied near the villageof Hille, situated north of the city of Gävle in central Sweden.

At the end of April 1986 reactor number 4 of the nuclear power plant at Chernobyl explod-ed and large amounts of radioactive particles were then released into the atmosphere due to both the explosion as well as the consecutive fire of the graphite core. A cloud of radioac-tivity was spread over the northern hemisphere, including Sweden, due to the prevailing wind directions. The radioactive particles were washed out from the cloud by rain and snowfall in some areas of Sweden and deposited on the ground. The deposited radionu-clides, primarily Cesium and iodine isotopes, were later absorbed into the soil and taken up by the roots of the plants. Some of these radionuclides, like 137Cs, still persist in some of the terrestrial ecosystems at relatively high concentrations which lead to contamination of the meat of moose, roe deer and wild boar even today.The two municipalities Heby and Uppsala, in the eastern part of central Sweden, experi-enced a relatively large deposition of 137Cs which resulted in high levels of 137Cs in moose and other game.

Kärnkraftsolyckan i Tjernobyl 1986 spred radioaktivt nedfall över Europa och Sverige som kom att tas upp i ekosystemet av växter, djur och människor. I Sverige innebar det att älg (Alces alces), rådjur (Capreolus capreolus) och ren (Rangifer tarandus) fick förhöjda halter av Cesium-137, 137Cs, som i sin tur togs upp av de människor som åt av köttet. Upptaget i ekosystemet påverkas av flera faktorer; jordmånen och dess förmåga att binda radionukleider, växter och svamps benägenhet att ta upp dem, hjortdjurens val av föda beroende på tillgång och årstid samt tiden på året som jägare och samer fäller hjortdjuren. Denna litteraturstudie ämnar ta reda på hur hjortdjur (Cervidae) och människor i Sverige påverkades av nedfallet. Utifrån de studier som granskats har inga rapporterat märkbar påverkan hos hjortdjur.

In April 1986 an accident occurred at the nuclear power station in Chernobyl. Radionuclides were spread all over Europe including Sweden. Today there are still measurable concentrations of 137Cs in the different ecosystems in the contaminated parts of Sweden. The wild boar is the second most popular game in Sweden and today the Swedish population consumes more wild boar meat than ever. As the wild boar population increases the wild boars are moving further north towards the contaminated areas, which creates an interest to study the state of 137Cs in wild boars in these areas. Muscle samples from wild boars collected during 2010-2013 were analyzed based on 137Cs content.

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in the event of rainfall. An increased level of radioactivity in the plants may occur due to interception and retention of the radionuclides. If the content of the plants is above the threshold limit value, entire yields may have to be destroyed. In order to prevent contamination or decrease the content countermeasures can be taken. The impact of the biomass, leaf area index (LAI) and growth stage of the plant on the interception and retention is important to know in order to decide which countermeasures to use. Weather may also be an important factor. In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley and spring oil-seed rape was studied.

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in theevent of rainfall. An increased level of radioactivity in the plants may occur due tointerception and retention of the radionuclides. If the content of the plants is above thethreshold limit value, entire yields may have to be destroyed. In order to preventcontamination or decrease the content countermeasures can be taken. The impact of thebiomass, leaf area index (LAI) and growth stage of the plant on the interception andretention is important to know in order to decide which countermeasures to use.Weather may also be an important factor.In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley andspring oil-seed rape was studied.

Gävle var en av de platser som fick mest radioaktivt nedfall efter Tjernobylolyckan 1986. Syftet med vår undersökning är att försöka få en förståelse för hur detta har påverkat kvinnor som bodde i Gävle 1986 och hur de känner idag. Vår frågeställning är vilka minnen de idag har kvar sedan tiden då olyckan hände och vad det betyder?Memory-work är utvecklad av Frigga Haug inom feministisk forskningstradition. Metoden är induktiv, såtillvida att resultaten tolkas utifrån de minnen som kommer fram i undersökningen och inte från färdiga teorier, och resultaten kan leda till nya frågeställningar.

Several radioactive nuclides were deposited in Sweden after the Chernobyl accident in 1986. The greatest attention was given to 137Cs because of its relative long physical half life of about 30 years. 137Cs will be present in nature for more than 100 years before it has vanished completely. When radiocaesium decays to a stable end product ionizing radiation is emitted, which can cause cancer in humans that has been exposed to a high radiation dose. Radiocaesium behaves like potassium and is easily taken up into biological systems.