Determination of total chlorine and bromine in solid wastes by sintering and inductively coupled plasma-sector field mass spectrometry

A sample preparation method based on sintering, followed by analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) for the simultaneous determination of chloride and bromide in diverse and mixed solid wastes, has been evaluated. Samples and reference materials of known composition were mixed with a sintering agent containing Na₂CO₃ and ZnO and placed in an oven at 560 °C for 1 h. After cooling, the residues were leached with water prior to a cation-exchange assisted clean-up. Alternatively, a simple microwave-assisted digestion using only nitric acid was applied for comparison. Thereafter the samples were prepared for quantitative analysis by ICP-SFMS. The sintering method was evaluated by analysis of certified reference materials (CRMs) and by comparison with US EPA Method 5050 and ion chromatography with good agreement. Median RSDs for the sintering method were determined to 10% for both chlorine and bromine, and median recovery to 96% and 97%, respectively. Limits of detection (LODs) were 200 mg/kg for chlorine and 20 mg/kg for bromine. It was concluded that the sintering method is suitable for chlorine and bromine determination in several matrices like sewage sludge, plastics, and edible waste, as well as for waste mixtures. The sintering method was also applied for determination of other elements present in anionic forms, such as sulfur, arsenic, selenium and iodine.     

Equity and sustainability over the next fifty years: An exercise in economic visioning

A simplistic aggregate model of global economic activity supports a 50-year visioning exercise with targets defined in terms of aggregate measures of global equity (convergence) and sustainability (contraction). Some ambitious combinations of these targets turn out to be infeasible even under the most favorable modeling assumptions. No contraction target (no reduction in fossil fuel consumption relative to the present) was possible, for example, if international capital transfers pushed per capita incomes in low-income countries above 33% of levels achieved in high-income countries. Lower prices for renewable alternatives to exhaustible resources generally made sustainability targets easier to achieve, but lower prices for renewable resources also made equity targets more difficult to achieve. Improved substitution between capital and labor made equity targets easier to achieve in relative terms, but improved substitution between capital and labor could make any given sustainability target more or less difficult to achieve. All the results suggest that it is possible to overstate the purported conflict between achieving sustainability and equity targets. The very transfers of international capital that would promote relative equity between high-income and low-income countries could also work to spread the incidence of achieving any sustainability target more evenly across their boundaries.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Individual preferences for reducing flood risk to near zero through elevation

Climate change is expected to increase the frequency and intensity of natural disasters. Adaptation investments are required in order to limit the projected increase in natural disaster risks. Adaptation measures can reduce risk partially or completely eliminate risk. The literature on behavioural economics suggests that individuals rarely undertake measures that limit risk partially, while they may place a considerable value on measures that reduce risk to zero. This is studied for a case of adaptation to climate change and its effects on flood risk in the Netherlands. In particular, we examine whether households are willing to invest in elevating newly built structures when this is framed as eliminating flood risk. The results indicate that a majority of homeowners (52%) is willing to make a substantial investment of €10,000 to elevate a new house to a level that is safe to flooding. Differences between willingness to pay (WTP) for flood insurance and WTP for risk elimination through elevation indicate that individuals place a considerable value on the latter adaptation option. This study estimates that the “safety premium” which individuals place on risk elimination is approximately between €35 and €45 per month. The existence of a safety premium has important implications for the design of climate change adaptation policies. The decision to invest in elevating homes is significantly correlated with the expected negative effects of climate change, perceptions of flood risks, individual risk attitudes, and living close to a main river.     

Ammonium in Fließgewässern des Saale-Einzugsgebietes

Exposure assessment of rarely measured substances or newly identified chemicals requires the usage of mathematical methods. The georeferenced exposure model GREAT-ER was designed to accurately predict the concentration of ‘down-the-drain’ chemicals under consideration of their spatial and temporal variability in surface waters. In the past, successful validations of the model have been performed predominantly for small and middle-sized catchments and were accompanied by extensive monitoring of the detergent-ingredients boron and linear alkylbenzene sulphonate (LAS). A proof of the adaptability of GREAT-ER to large catchments is given here by example of the Saale river basin. Furthermore, it could be shown that ammonium is a suitable parameter for validations of the model. This corroborated the hypothesis that the non-point-emissions of ammonium are of less importance in comparison to the ammonium loads in the effluents of wastewater treatment plants.     

Isolated sulfite oxidase deficiency: mutation analysis and DNA-based prenatal diagnosis

Isolated sulfite oxidase deficiency is an autosomal recessive, neurological disorder resulting from a defect in SUOX, the gene encoding the enzyme that catalyzes the terminal reaction in the sulfur amino acid degradation pathway. In its classical, severe form, sulfite oxidase deficiency leads to intractable seizures, severe and progressive brain pathology and death at an early age. We report here on clinical features and mutational analysis of the genetic defect in a newborn with sulfite oxidase deficiency. Cultured fibroblasts from this patient exhibited no detectable sulfite oxidase activity, and a unique four base pair deletion was present in the cDNA isolated from the same source. Identification of the same genetic defect in a heterozygous state in each of the parents and the monitoring of subsequent pregnancies in this family by DNA-based prenatal diagnosis are also described. The deletion mutation was identified in a homozygous state in uncultured chorionic villus tissue from the second pregnancy that was subsequently terminated. In the third pregnancy, the presence of sulfite oxidase activity and identification of the mutation in a heterozygous state suggested that the fetus was not affected. This pregnancy resulted in the birth of a normal child. Copyright © 2002 John Wiley & Sons, Ltd.