Uranium Content in Plants and Vegetation

Plants can serve as bioaccumulators of uranium, a topic that has recently received special attention after the accidents at the Chernobyl and Fukushima nuclear power plants. Frame 3.1 verbally quotes parts of a notice published in one of the leading scientific journals in the field of environmental monitoring (CaldweU et al. 2012). 

Several of the methods mentioned earlier for the determination of the uranium content in soil are also suitable for assaying the uranium content in plants. However, there are two major differences the uranium concentration in plants is usually significantly lower than in soil and the fraction of organic matter and the moisture content in plants are much higher than in soil. These two factors dictate somewhat different sample preparation methodologies and more sensitive analytical devices are preferred as shown in the following examples. Some of the review articles mentioned earlier also discuss the uramum content, uptake (transfer factor), and distribution in plants (Zavodska et al. 2008 Mitchell et al. 2013). One of the most comprehensive sources listing the uranium content in many different types of plants is the Canadian report mentioned earlier (Environment 2007). An additional important source can be found in the report published by the IAEA (IAEA 2010). 

Caldwell provided the justification for publishing the article (Caldwell et al. 2012) and stated that after the accidents at Fukushima aud Chernobyl there is an urgent need to characterize the bio-availability and transport potential of radionuclides such as uranium that are associated with the nuclear fuel cycle. This information cannot be solely inferred from abiotic sampling when considering the interacting chemical, biological and physical processes as they influence contaminant behavior within an ecosystan. The accumulation of radionuclides in plants reflects the level of contamination and is indicative of the bioavailability of these contaminants in the food chain. Furthermore, certain plants can serve as selective biomonitors of radionuclides. 

In another study, the uranium content in four types of plants and plant components growing in a boreal forest in Finland a microwave digestion procedure was 

Uranium Content and Biomass of Tree Components and Humus in the Pine Stand Growing on U-Mining Dump H382 and Estimation of the Total U Amount and Its Relative Distribution between Tree Components and at Stand Level 

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Highlights. The analytical methods used for determining the uranium content in plants and vegetation and the sample preparation techniques follow the same principles detailed earlier for soil and sediment samples. A generic flowchart of preparation of vegetation samples for analysis is shown in Figure 3.10. These steps include... 

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