Radioecology for boreal ecosystems: studies on transfer processes and effects on wildlife

作     者：Majlesi, Soroush 

作者单位：University of Eastern Finland 

学位级别：博士

导师姓名：Jukka Juutilainen;Jonne Naarala;Christina Biasi

授予年度：2021年

摘      要：Nuclear power is an important source of energy and a means to decrease the use of fossil fuels and to manage the climate crisis. One of the main challenges of this technology, however, is management of radioactive waste that could be released into the biosphere. Radionuclides, released into the environment due to poor man- agement of radioactive waste, may incorporate into various environmental compo- nents and be assimilated by flora and fauna as parts of the food web. This study focused on understanding the transfer of radionuclides in aquatic and terrestrial ecosystems as well as on possible effects on the wildlife. Transfer of 14 C from soil to two plant species was investigated on a peatland site by using a novel approach to distinguish between soil and atmosphere as sources of C. The aim of this study was to determine the contribution of soil-derived C to plant C on a site where a large difference in 14 C/total C ratio between modern air and up to 8000-year leftover peat exists. This yields an ideal opportunity to track the contribu- tion of atmospheric C and soil-derived C in plants growing on the peatland. The results showed higher contribution of soil C in plant roots (up to 5%), while no contribution was observed in above-ground parts despite up to 14% of soil-derived C being available in the canopy. The findings suggested that 14 C possibly released from radioactive waste has low potential to further distribute to above-ground parts of the biosphere, which is mainly supported by plants through photosynthe- sis. Transfer of Cl, Co, Mo, Ni, Se, Sr, U and Zn into freshwater species, chironomid larvae (Chironomus sp.), roach (Rutilus rutilus) and perch (Perca fluviatilis) was inves- tigated in three ponds. These elements are important in safety assessment of radio- active waste. The study was carried out at two ponds near a former uranium mine and a reference pond, located further away from the mining area. Overall, the con- centration of elements in media an