Composition of plastics from waste electrical and electronic equipment (WEEE) by direct sampling

This paper describes a direct analysis study carried out in a recycling unit for waste electrical and electronic equipment (WEEE) in Portugal to characterize the plastic constituents of WEEE. Approximately 3400 items, including cooling appliances, small WEEE, printers, copying equipment, central processing units, cathode ray tube (CRT) monitors and CRT televisions were characterized, with the analysis finding around 6000 kg of plastics with several polymer types. The most common polymers are polystyrene, acrylonitrile-butadiene-styrene, polycarbonate blends, high-impact polystyrene and polypropylene. Additives to darken color are common contaminants in these plastics when used in CRT televisions and small WEEE. These additives can make plastic identification difficult, along with missing polymer identification and flame retardant identification marks. These drawbacks contribute to the inefficiency of manual dismantling of WEEE, which is the typical recycling process in Portugal. The information found here can be used to set a baseline for the plastics recycling industry and provide information for ecodesign in electrical and electronic equipment production.     

Aerobic Biodegradation of Polymers in Solid-State Conditions: A Review of Environmental and Physicochemical Parameter Settings in Laboratory Simulations

During the last few years, biodegradable polymers have been developed to replace petrochemical polymers. Until now, research devoted to these polymers essentially focused on their biodegradability. There is now a need to bear out their nontoxicity. To verify this, the biodegradation must be carried out in accelerated laboratory tests which allow the metabolites and residues to be recovered. To reproduce the natural conditions (compost, field) as closely as possible, degradation experiments must be run on solid-state substrates. We review studies of aerobic degradation in solid-state substrates. This article focuses in particular on the environmental, physical, and chemical parameters (such as substrate nature, moisture, temperature, C/N ratio, and pH) that influence biodegradation kinetics. This study also aims at finding the solid substrate most adapted to residues and metabolite recovery. The most significant parameters would appear to be the substrate type, moisture content, and temperature. Inert substrates such as vermiculite are well suited to residue extraction. This review also opens the field to new research aimed at optimizing conditions for aerobic solid-state biodegradation and at recovering the metabolites and residues of this degradation process.     

Scaling range sizes to threats for robust predictions of risks to biodiversity

Assessments of risk to biodiversity often rely on spatial distributions of species and ecosystems. Range‐size metrics used extensively in these assessments, such as area of occupancy (AOO), are sensitive to measurement scale, prompting proposals to measure them at finer scales or at different scales based on the shape of the distribution or ecological characteristics of the biota. Despite its dominant role in red‐list assessments for decades, appropriate spatial scales of AOO for predicting risks of species’ extinction or ecosystem collapse remain untested and contentious. There are no quantitative evaluations of the scale‐sensitivity of AOO as a predictor of risks, the relationship between optimal AOO scale and threat scale, or the effect of grid uncertainty. We used stochastic simulation models to explore risks to ecosystems and species with clustered, dispersed, and linear distribution patterns subject to regimes of threat events with different frequency and spatial extent. Area of occupancy was an accurate predictor of risk (0.81<|r|<0.98) and performed optimally when measured with grid cells 0.1–1.0 times the largest plausible area threatened by an event. Contrary to previous assertions, estimates of AOO at these relatively coarse scales were better predictors of risk than finer‐scale estimates of AOO (e.g., when measurement cells are <1% of the area of the largest threat). The optimal scale depended on the spatial scales of threats more than the shape or size of biotic distributions. Although we found appreciable potential for grid‐measurement errors, current IUCN guidelines for estimating AOO neutralize geometric uncertainty and incorporate effective scaling procedures for assessing risks posed by landscape‐scale threats to species and ecosystems.     

A novel multi-model data-driven ensemble approach for the prediction of particulate matter concentration

Environmental Science and Pollution Research - Accuracy in the prediction of the particulate matter (PM2.5 and PM10) concentration in the atmosphere is essential for both its monitoring and...     

Nitrate levels in shallow groundwater of upstate New York,USA

This paper summarizes research evaluating nitrate levels in shallow groundwater of upstate New York, USA. Water from abandoned dug wells in six different land-use categories was analyzed for nitrate. Findings indicate that regardless of overlying land-use, shallow groundwater is susceptible to high levels of nitrate. Over 60 percent of the water samples tested, including at least one sample from each land-use category, had nitrate levels in excess of the United States drinking water standard of 10 mg 1^–1. Due to the potential threat of elevated nitrate levels, efforts should be made to eliminate abandoned dug wells in shallow groundwater as a source of water supply.Glenn Harris is with the Environmental Studies Programme of St Lawrence University in Canton, New York. Brian Henry is with the Department of Entomology at the University of Georgia in Athens, Georgia. Jeffrey Deyette is with the joint International Relations and Resource and Environmental Management Programme at Boston University in Boston, Massachusetts. This research was performed as a Community Service Project sponsored by the Mergardt Fund while Mr Henry and Mr Deyette were students under the supervision of Dr Harris at St Lawrence University.     

Formulation of cleanup standards for trace elements with probability plots

Probability plots of trace element concentrations may be used to partition, or segregate, sample data into its constituent populations. Two populations are typically present in data from sites requiring remedial action, one representing clean, uncontaminated soil or sediment (background) and the other representing contaminated ground. The use of such plots in the analysis and evaluation of environmental data permits a statistical characterization of the background populations, from which defensible cleanup criteria may be developed. These criteria will be environmentally conservative, yet will minimize the amount of soil removed in a remedial action. An example is given from a successful cleanup of a surface impoundment.     

Subject Index

Subject Index

Subject Index     

Prenatal exclusion of X-linked hydrocephalus-stenosis of the aqueduct of sylvius sequence using closely linked DNA markers

X-linked hydrocephalus-stenosis of the aqueduct of Sylvius sequence (H-SAS, MIM number 307 000) is a rare genetic disorder characterized by hydrocephalus, macrocephaly, adducted thumbs, spasticity, mental retardation, and cerebral malformations. This regularly lethal condition is usually diagnosed at birth or prenatally by ultrasound, but hydrocephalus may be moderate or even undetectable on fetal ultrasound examination. Moreover, since heterozygous women are asymptomatic, carrier detection is at present impossible before the birth of an affected son. Therefore, mapping the H-SAS locus to distal Xq (Xq28) was of primary importance for genetic counselling and prenatal diagnosis. Here, we report prenatal exclusion of H-SAS with a probability of 97.6 per cent in two male fetuses with a 50 per cent a priori risk of being affected using closely linked Xq28 DNA markers.     

Factor Biases and Promoting Sustainable Development: Adaptation to Drought in the Senegal River Basin

The ongoing drought in the Sahel region of West Africa highlights the vulnerability of food-producing systems to climate change and variability. Adaptation to climate should therefore increase the sustainability of agriculture under a long-term drought. Progress towards sustainability and adaptation in the the Senegal River Basin is hampered by an existing set of social and ecological relationships that define the control over the means of production and how people interact with their environment. These relationships are sensitive to the technological inputs and the administration of food production, or the factor bias in the different policy alternatives for rural development. One option is based on state-controlled, irrigated plantations to provide rice (Oryza) for the capital, Dakar. This policy emphasizes a top-down management approach, mechanized agriculture and a reliance on external inputs which strengthens the relationships introduced during the colonial period. A time series decomposition of the annual flow in the Senegal River at Bakel in Senegal suggests that water resources availability has been substantially curtailed since 1960, and a review of the water resources budget or availability in the basin suggests that this policy's food production system is not sustainable under the current climate of the basin. Under these conditions, this program is exacerbating existing problems of landscape degradation and desertification, which increases rural poverty. A natural resource management policy offers two adaptation strategies that favour decentralized management and a reduction of external inputs. The first alternative, “Les Perimetres Irrigués”, emphasizes village-scale irrigation, low water consumption cereal crops and traditional socio-political structures. The second alternative emphasizes farm-level irrigation and agro-forestry projects to redress the primary effects of desertification.