A discourse-analytical perspective on sustainability assessment: interpreting sustainable development in practice

Sustainable development is a ubiquitously used concept in public decision-making: it refers to an ideal vision of global society where human development and environmental quality go hand in hand. Logically, any decision-supporting process aiming at facilitating and steering society toward a sustainable future then seems desirable. Assessing the sustainability of policy decisions is, however, influenced by what sustainable development is believed to entail, as different discourses coexist under the umbrella of the sustainable development meta-discourse. This paper proposes a typology of sustainable development discourses, and, subsequently, applies a discourse-analytical lens on two practical cases of sustainability assessment in different institutional and geographical contexts (in Belgium and in Benin). The results indicate that sustainability assessments tend to be influenced mainly by the consensual ‘sustainable development as integration’ discourse, while also providing a forum for dialogue between different discourses. The results shed light on context-specific discursive and institutional dynamics for the development and application of sustainability assessment. Acknowledging these dynamics as well as sustainable development’s inherent interpretational limits can lead to an improved use of sustainable development as a decision-guiding strategy.     

(137)Cs and (90)Sr uptake by sunflower cultivated under hydroponic conditions

The (90)Sr and (137)Cs uptake by the plant Helianthus annuus L. was studied during cultivation in a hydroponic medium. The accumulation of radioactivity in plants was measured after 2, 4, 8, 16 and 32 days of cultivation. About 12% of (137)Cs and 20% of (90)Sr accumulated during the experiments. We did not find any differences between the uptake of radioactive and stable caesium and strontium isotopes. Radioactivity distribution within the plant was determined by autoradiography. (137)Cs was present mainly in nodal segments, leaf veins and young leaves. High activity of (90)Sr was localized in leaf veins, stem, central root and stomata. The influence of stable elements or analogues on the transfer behaviour was investigated. The percentage of non-active caesium and strontium concentration in plants decreased with the increasing initial concentration of Cs or Sr in the medium. The percentage of (90)Sr activity in plants decreased with increasing initial activity of the nuclide in the medium, but the activity of (137)Cs in plants increased. The influence of K(+) and NH(4)(+) on the uptake of (137)Cs and the influence of Ca(2+) on the uptake of (90)Sr was tested. The highest accumulation of (137)Cs (24-27% of the initial activity of (137)Cs) was found in the presence of 10 mM potassium and 12 mM ammonium ions. Accumulation of about 22% of initial activity of (90)Sr was determined in plants grown on the medium with 8 mM calcium ions.     

Fractionation of natural radionuclides in soils from a uranium mineralized area in the south-west of Spain

A new version of a classical method was applied to study the distribution of natural radionuclides (238U, 230Th, and 226Ra) in the soil fractions obtained by a sequential extraction procedure. The potential significance of the fractions obtained with this method was tested on two very similar soils but with very different contents of the three radionuclides, collected in the proximity of a disused uranium mine located in the Extremadura region in the south-west of Spain. The results confirmed that, if only non-residual fractions are considered, the sequential method applied shows a characteristic speciation pattern of these natural radionuclides in this soil matrix, i.e., the distribution of each of the three radionuclides was very similar for the two soil samples.