Test of aerobic TCE degradation by willows (Salix viminalis) and willows inoculated with TCE-cometabolizing strains of Burkholderia cepacia

Environmental Science and Pollution Research - Trichloroethylene (TCE) is a widespread soil and groundwater pollutant and clean-up is often problematic and expensive. Phytoremediation may be a...     

Properties of Glauconite/Polyaniline Composite Prepared in Aqueous Solution of Citric Acid

Hybrid composite made of glauconite and polyaniline was prepared in aqueous solution of citric acid. Scanning electron microscopy combined with energy dispersive X-ray analysis shows uniform aggregates made of glauconite microparticles and polyaniline matrix. The results of X-ray powder diffraction suggest that: (1) citric acid used for the polymerisation of aniline causes formation of emeraldine salt where macromolecular ordering in the amorphous polymer takes place; (2) no chemical interaction between glauconite and emeraldine takes place in the prepared composite. FT-IR spectra of the prepared polymer and composite show features indicating all the functional groups that are present in the diiminoquinone–diaminobenzene state of polyaniline. Thermal stability of the composite was higher than the prepared polymer suggesting the occurrence of an interphase interaction between glauconite and emeraldine. After pyrolysis in purified nitrogen the composite still remained glauconite, and ε-Fe3N together with amorphous and graphitic carbon were found as reaction products. The values of electrical conductivity and magnetization of the composite suggest that optimization of these values might be achieved based upon the relationship between glauconite and polyaniline.     

Effect of risk aversion on prioritizing conservation projects

Conservation outcomes are uncertain. Agencies making decisions about what threat mitigation actions to take to save which species frequently face the dilemma of whether to invest in actions with high probability of success and guaranteed benefits or to choose projects with a greater risk of failure that might provide higher benefits if they succeed. The answer to this dilemma lies in the decision maker's aversion to risk—their unwillingness to accept uncertain outcomes. Little guidance exists on how risk preferences affect conservation investment priorities. Using a prioritization approach based on cost effectiveness, we compared 2 approaches: a conservative probability threshold approach that excludes investment in projects with a risk of management failure greater than a fixed level, and a variance‐discounting heuristic used in economics that explicitly accounts for risk tolerance and the probabilities of management success and failure. We applied both approaches to prioritizing projects for 700 of New Zealand's threatened species across 8303 management actions. Both decision makers’ risk tolerance and our choice of approach to dealing with risk preferences drove the prioritization solution (i.e., the species selected for management). Use of a probability threshold minimized uncertainty, but more expensive projects were selected than with variance discounting, which maximized expected benefits by selecting the management of species with higher extinction risk and higher conservation value. Explicitly incorporating risk preferences within the decision making process reduced the number of species expected to be safe from extinction because lower risk tolerance resulted in more species being excluded from management, but the approach allowed decision makers to choose a level of acceptable risk that fit with their ability to accommodate failure. We argue for transparency in risk tolerance and recommend that decision makers accept risk in an adaptive management framework to maximize benefits and avoid potential extinctions due to inefficient allocation of limited resources. El Efecto de la Aversión de Riesgo sobre la Priorización de Proyectos de Conservación     

Blei- und Cadmiumbelastung Zähne als Indikatoren der Blei- und Cadmiumbelastung des Menschen

The levels of lead and cadmium were determined in deciduous teeth of children from different areas of Northrhine-Westfalia, Germany. The children were born in 1968–1973 and 1979–1986. The levels of lead and cadmium in deciduous teeth show a significant decrease within this time interval. Lead decreases about 50 %, cadmium about 60 %. Since tooth lead and tooth cadmium may be used as indicators of the lead and cadmium body burden, the results of this study indicate a significant decrease of population exposure to lead and cadmium in West-Germany during the past 20–25 years, which is a consequence of pollution control and the increasing use of unleaded fuel.     

Radioaktive Isotope in Sedimenten

The Federal Office for Radiation Protection investigated several natural and artificial radioactive isotopes in the sediments of rivers in the Erzgebirge by means of gamma radiation spectrometry. The regional distribution of the isotopes and their relation to former uranium mining is described. The significantly high differences of their concentrations in different river sections are discussed. A dependence of the activity concentrations on temporal peaks in mining activities is illustrated by the example of a sediment profile. The behavior of artificial radioactive isotopes, such as¹³⁷Cs and¹³⁴Cs after the reactor accident in Tschernobyl is characterized. All measurements were evaluated from the radiological point of view and critically assessed.