Uptake of 14C-atropine and/or its transformation products from soil by wheat (Triticum aestivum var Kronjet) and their translocation to shoots

Plant uptake of toxins and their translocation to edible plant parts are important processes in the transfer of contaminants into the food chain. Atropine, a highly toxic muscarine receptor antagonist produced by Solanacea species, is found in all plant tissues and can enter the soil and hence be available for uptake by crops. The absorption of atropine and/or its transformation products from soil by wheat (Triticum aestivum var Kronjet) and its distribution to shoots was investigated by growing wheat in soil spiked with unlabeled or ¹⁴C-labeled atropine. Radioactivity attributable to ¹⁴C-atropine and its transformation products was measurable in plants sampled at 15 d after sowing (DAS) and thereafter until the end of experiment. The highest accumulation of ¹⁴C-atropine and/or its transformation products by plants was detected in leaves (between 73 and 90% of the total accumulated) with lower amounts in stems, roots, and seeds (approximately 14%, 9%, and 3%, respectively). ¹⁴C-Atropine and/or its transformation products were detected in soil leachate at 30, 60, and 90 DAS and were strongly adsorbed to soil, with 60% of the applied dose adsorbed at 30 DAS, plateauing at 70% from 60 DAS. Unlabeled atropine was detected in shoots 30 DAS at a concentration of 3.9 ± 0.1 μg kg^?1 (mean ± SD). The observed bioconcentration factor was 2.3 ± 0.04. The results suggest a potential risk of atropine toxicity to consumers.     

In‐well sediment incubators to evaluate microbial community stability and dynamics following bioimmobilization of uranium

An in‐well sediment incubator (ISI) was developed to investigate the stability and dynamics of sediment‐associated microbial communities to prevailing subsurface oxidizing or reducing conditions. Herein we describe the use of these devices at the Old Rifle Uranium Mill Tailings Remedial Action (UMTRA) site. During a seven‐month period in which oxidized Rifle Aquifer background sediment (RABS) were deployed in previously biostimulated wells under iron‐reducing conditions, cell densities of known iron‐reducing bacteria, including Geobacteraceae, increased significantly, showing the microbial community response to local subsurface conditions. Phospholipid fatty acid (PLFA) profiles of RABS following in situ deployment were strikingly similar to those of adjacent sediment cores, suggesting ISI results could be extrapolated to the native material of the test plots. Results for ISI deployment with laboratory‐reduced sediments showed only slight changes in community composition and pointed toward the ability of the ISI to monitor microbial community stability and response to subsurface conditions. © 2009 Wiley Periodicals, Inc.     

Uranium removal from groundwater via in situ biostimulation: Field-scale modeling of transport and biological processes

During 2002 and 2003, bioremediation experiments in the unconfined aquifer of the Old Rifle UMTRA field site in western Colorado provided evidence for the immobilization of hexavalent uranium in groundwater by iron-reducing Geobacter sp. stimulated by acetate amendment. As the bioavailable Fe(III) terminal electron acceptor was depleted in the zone just downgradient of the acetate injection gallery, sulfate-reducing organisms came to dominate the microbial community. In the present study, we use multicomponent reactive transport modeling to analyze data from the 2002 field experiment to identify the dominant transport and biological processes controlling uranium mobility during biostimulation, and determine field-scale parameters for these modeled processes. The coupled process simulation approach was able to establish a quantitative characterization of the principal flow, transport, and reaction processes based on the 2002 field experiment, that could be applied without modification to describe the 2003 field experiment. Insights gained from this analysis include field-scale estimates of the bioavailable Fe(III) mineral threshold for the onset of sulfate reduction, and rates for the Fe(III), U(VI), and sulfate terminal electron accepting processes.     

Barriers to the long‐term recovery of individuals with disabilities following a disaster

This study examines how pre‐existing disabling conditions influenced the recovery process of survivors of Hurricane Katrina. It focuses specifically on the barriers that hindered the recovery process in these individuals. Focus groups were convened in four Gulf Coast states with 31 individuals with disabilities who lived in or around New Orleans, Louisiana, prior to Hurricane Katrina in August 2005. Qualitative data were analysed using grounded theory methodology. Five themes emerged as the most significant barriers to recovery: housing; transportation; employment; physical and mental health; and accessing recovery services. While these barriers to recovery were probably common to most survivors of the disaster, the research results suggest that disability status enhanced the challenges that participants experienced in negotiating the recovery process and in acquiring resources that accommodated their disabilities. The findings indicate that, when disaster recovery services and resources did not accommodate the needs of individuals with disabilities, recovery was hindered. Recovery efforts should include building accessible infrastructure and services that will allow for participation by all.     

Field‐scale uranium (VI) bioimmobilization monitored by lipid biomarkers and 13C‐acetate incorporation

At the Old Rifle uranium mill‐tailing site in eastern Colorado, a test of subsurface amendment with acetate to stimulate the reductive immobilization of uranium was monitored by using lipid biomarker analysis and incorporation of ¹³C‐labeled acetate into lipid biomarkers. Both sediment and groundwater samples were analyzed. Within 7 days of acetate addition, groundwater microbial biomass increased by a factor of 5, and remained higher than control values in most samples for the 28 days sampled. At 29 days after the beginning of acetate amendment, 4 of 12 sediment samples had microbial biomass greater than the 95 percent confidence interval of controls. The mole percents of the phospholipid fatty acids 16:1ω7c and 16:1ω5c increased over control values upon acetate amendment, and incorporated high levels of ¹³C from labeled acetate in groundwater and sediment samples. 16:1ω7c is a biomarker for Geobacter, and evidence is provided that 16:1ω5c represents an unidentified iron‐reducing bacterium, probably a member of the Desulfobulbaceae. Biomarkers for organisms other than iron‐reducing bacteria, iso‐ and anteiso‐branched fatty acids and 18:1ω9c, decreased upon acetate amendment, and had their highest stable isotope incorporation at least 4 days after labeled acetate amendment ended, evidence for carbon‐sharing between iron‐reducers and other microorganisms. © 2011 Wiley Periodicals, Inc.     

The Ythan Project: A Case Study on Improving Catchment Management through Community Involvement

Increased participation in resource management decisions by a wide range of stakeholders has been widely advocated, and has recently been formally incorporated into the European Water Framework Directive. However, achieving such participation has generally proved to be problematical. In response to locally perceived needs, a project was set up in the Ythan catchment in northeast Scotland, to undertake catchment management actions with increased public involvement. This paper outlines the methods used to increase public participation in such actions, and some preliminary assessments of the effectiveness of these. The experience of the project and the lessons learnt, including some of the difficulties of ensuring fully representative stakeholder involvement, are discussed in relation to published criteria for public participation in resource management.     

Influence of cosolvents on quinoline sorption by subsurface materials and clays

Quinoline sorption was measured on Na-saturated subsurface materials, a natural clay isolate, and montmorillonite, and was dominated by exchange of the quinolinium ion. In water/methanol and water/acetone mixtures, quinoline sorption on the subsoils and clays was lower than from water. In cosolvent, sorption followed the ionization fraction indicating the continued predominance of ion exchange. The reduction in quinoline sorption by cosolvent was similar for all the subsoils and clays indicating commonality in the surface-solute-solvent interaction. Conditional equilibrium constants (_cK_ex) for quinoline exchange on the subsoils in water/methanol mixtures decreased log-linearly with mole percent cosolvent up to 20% methanol. This decrease closely followed the increase in quinoline solubility in the cosolvent mixtures. Acetone caused greater reduction in sorption than methanol, at comparable mole percent, in accordance with its lower dielectric constant and enhanced solvating power. A generalized thermodynamic approach based on the concept of transfer activity coefficients was developed to account for the cosolvent effect on _cK_ex, and was successfully applied to the quinoline sorption data. The thermodynamic analysis suggested that enhanced solvation of the organic cation in the bulk solvent and desolvation of Na⁺ at the charged surface predominate the cosolvent effect.