A free-enzyme catalyst for the bioremediation of environmental atrazine contamination

Herbicide contamination from agriculture is a major issue worldwide, and has been identified as a threat to freshwater and marine environments in the Great Barrier Reef World Heritage Area in Australia. The triazine herbicides are of particular concern because of potential adverse effects, both on photosynthetic organisms and upon vertebrate development. To date a number of bioremediation strategies have been proposed for triazine herbicides, but are unlikely to be implemented due to their reliance upon the release of genetically modified organisms. We propose an alternative strategy using a free-enzyme bioremediant, which is unconstrained by the issues surrounding the use of live organisms. Here we report an initial field trial with an enzyme-based product, demonstrating that the technology is technically capable of remediating water bodies contaminated with the most common triazine herbicide, atrazine.     

Response to the environmental and welfare imperatives by U.K. Livestock production industries and research services

Production methods for food from U.K. livestock industries (milk, dairy products, meat, eggs, fibre) are undergoing substantial change as a result of the need to respond to environmental and animal welfare awareness of purchasing customers, and to espouse the principles of environmental protection. There appears to be a strong will on the part of livestock farmers to satisfy the environmental imperative, led by the need to maintain market share and by existing and impending legislation. There has been support forthcoming in the form of Government-sponsored scientific research and technological development to provide the necessary framework for new environmentally sensitive practices. The agricultural community has itself made substantial responses to market demand through the inception of Farm Assured Quality Assurance Schemes. These appear to have a more sustainable future than the extremes of organic farming and free-range practices. Pollution of agricultural land with nitrate and phosphate by intensive livestock industries is a greater problem in some parts of continental Europe than it is in the U.K. The distribution of livestock out of intensive units and into mixed farming systems, would require substantial restructuring of the industry. Many of the animal welfare requirements which have been forwarded as a part of the environmental agenda for agriculture have been voluntarily accepted by livestock producers. However, some major aspects, such as alternative housing systems for pigs and poultry, remain unresolved. Analysis of the science and technology support for the environmental imperative, especially from Government sources, would suggest that, although dramatically increased in recent years, environmentally orientated research remains a relatively small proportion of the whole. Whilst a movement away from governmental funding of volume production appears to be justifiable, there has not been an equivalent balancing of effort toward funding for product quality, sustainability, environmental protection and animal welfare. Nevertheless, the university education system is producing a generation of more environmentally aware agricultural science graduates who are opting to pursue Government-sponsored environmentally orientated postgraduate research programs.     

Assessing national sustainable development strategies: Strengthening the links to operational policy

At the Earth Summit in Rio de Janeiro in 1992, it was agreed that all countries should develop a national sustainable develop‐ment strategy (NSDS) as a key component of implementing the goals of Agenda 21. Progress has been limited. Few countries have established a formal strategy, and many of the strategies that exist have been only partially implemented. This article proposes an approach that addresses the need to improve existing strategic planning mechanisms. The approach is based on a periodic assessment of existing systems, to evaluate the extent to which they incorporate NSDS principles, and identify areas to be strengthened. The article describes an assessment methodology, presents examples of its use, and discusses ways in which current approaches to NSDS may be complemented by continual review and improvement of existing planning processes.     

Sustainable Tourism and the Touristic Ecological Footprint

There is growing interest in ecological footprint analysis in aiding our understanding of societal demands upon the biosphere. Increasingly, attention is being focused on potential new applications of the technique. Tourism is one of the world's largest industries and can play a major part in encouraging more consumerist lifestyles. It is now widely accepted that tourism development may have profound impacts on local environments, and that, consequently, the sustainable development of tourism at destination areas is an important issue. However, sustainable tourism studies rarely look beyond the destination area, and there has been no substantive recognition of the wider ecological footprint of tourism activities. This paper attempts to connect, conceptually, the realms of sustainable tourism and ecological footprint thinking. In so doing, various conceptualisations of the 'touristic ecological footprint' (TEF) are suggested, along with some potential applications. It is argued that primary research should focus on calculating the touristic ecological footprint associated with individual tourism products, throughout the product's life-cycle. As well as bringing another dimension to our understanding of tourism's actual ecological demand, it is also argued that the concept of the touristic ecological footprint may be used to clarify theoretical aspects of the sustainable tourism debate, helping to rejuvenate this debate in the process.     

Automatic sorting of ichthyoplankton; Factors controlling plankton density in gradients of silica

Following isopycnic sedimentation in density gradients of colloidal silica (Ludox AM), zooplankton segregated into 3 broad bands of increasing density which included, respectively, fish eggs, invertebrates, and fish larvae. The zone of fish eggs was contaminated with Sagitta spp. and the zone of fish larvae was overlapped partially by mysids and euphausids. We have sought to minimize contamination through modifications of the silica gradients which might shift banding densities of the ichthyoplankton or of the contaminating invertebrates. Density shifts in fact occurred in different commercial formulations of silica sols and in gradients modified by small amounts of polymers, osmotica or charged small molecules. Sagitta were specifically shifted out of the zone of fish eggs by the addition, of 1% w/v dextran sulfate or in a silica sol composed of very small particles of silica (Nalcoag 1115). Fish larvae were shifted to higher densities by the addition of 1% w/v trimetaphosphate or 1% w/v dextran sulfate. Additions of 1% w/v polyvinyl alcohol, and of 10 mM glycine, and potassium phosphate had intermediate effects. The same banding densities of plankton in silica gradients were reached in less than 10 h at one gravity, independent of the immediate pretreatment of the sample.     

Metabolism of crufomate (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate) administered topically to a sheep.

A sheep dosed topically with 14C-crufomate (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate) excreted 45.5% of the 14C dose in the urine within 9 days. The feces contained 1.2% and the carcass 40.4% (this included the 37.7% of the dose remaining on the skin in the dosing area) of the dose. At sacrifice, the fat, liver, kidney, lung, and skin (where the dose was applied) contained the highest concentrations of 14C. Fourteen urinary metabolites were isolated and characterized by mass spectrometry. The metabolic reactions involved were oxidations of the t-butyl moiety, O-demethylation, replacement of the H-N-CH3 moiety with a hydroxyl group, oxidation of the N-methyl group to yield N-formyl phosphoramidates, hydrolysis of the phosphoramidate moiety to yield phenols, conjugation with glucuronic acid and combinations of these reactions.     

Sensitivity and first-step uncertainty analyses for the preferential flow model MACRO

Sensitivity analyses for the preferential flow model MACRO were carried out using one-at-a-time and Monte Carlo sampling approaches. Four different scenarios were generated by simulating leaching to depth of two hypothetical pesticides in a sandy loam and a more structured clay loam soil. Sensitivity of the model was assessed using the predictions for accumulated water percolated at a 1-m depth and accumulated pesticide losses in percolation. Results for simulated percolation were similar for the two soils. Predictions of water volumes percolated were found to be only marginally affected by changes in input parameters and the most influential parameter was the water content defining the boundary between micropores and macropores in this dual-porosity model. In contrast, predictions of pesticide losses were found to be dependent on the scenarios considered and to be significantly affected by variations in input parameters. In most scenarios, predictions for pesticide losses by MACRO were most influenced by parameters related to sorption and degradation. Under specific circumstances, pesticide losses can be largely affected by changes in hydrological properties of the soil. Since parameters were varied within ranges that approximated their uncertainty, a first-step assessment of uncertainty for the predictions of pesticide losses was possible. Large uncertainties in the predictions were reported, although these are likely to have been overestimated by considering a large number of input parameters in the exercise. It appears desirable that a probabilistic framework accounting for uncertainty is integrated into the estimation of pesticide exposure for regulatory purposes.     

Aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in sediments collected from the 110 mile hole and along a transect from 58 degrees 58.32'N 1 degree 10.38'W to the inner Moray Firth,Scotland

Sediments were collected from the 110 mile hole and along a transect from 58 degrees 58.32' N 1 degree 10.38' W to the UK National Marine Monitoring (NMMP) site in the inner Moray Firth, for determination of hydrocarbon concentration and composition. Total PAH concentrations (2- to 6-ring PAHs, parent and branched) were highest at NMMP site 95 and at the associated end of the transect in the inner Moray Firth. PAHs in this area were of predominately pyrolytic origin and could be attributed to urban and industrial activities. The majority of sediments collected in the middle section of the transect had low total PAH concentrations (< 100 ng g(-1) dry weight). The high proportion of naphthalenes and alkylated PAHs in this area suggested a predominately petrogenic input. The GC-FID aliphatic hydrocarbon profiles showed that the majority of sediments, including those in the inner Firth, had a limited petrogenic input. This was supported by the geochemical biomarker profiles, which contained triterpanes typical of Middle Eastern crude oil. Principal component analysis was used to investigate spatial trends in the PAH distributions and demonstrated that there were differences between areas. The NMMP site 95 and transect start and middle sediments were well separated. PCA further confirmed that sediments from the NMMP site 95, the 110 mile hole and the inner Moray Firth (south west) end of the transect contained PAHs from predominately pyrolytic sources, whereas sediments from the north east end (start) and the middle of the transect were typified by a greater petrogenic component.     

Suburbanization and drought: A mixed methods vulnerability assessment in rainy Massachusetts

This paper presents evidence that water restrictions in suburbanizing eastern Massachusetts towns are becoming more common, controlling for climate. We then assess the relationship between these suburban droughts and residential development. Focusing on the suburbs of Boston, seven towns independent of the Boston water supply system were selected to represent differing levels of sprawl-style growth. Water restrictions are becoming more frequent in all of the towns studied, and models demonstrate that restrictions are increasing in duration, independent of climate. Interviews suggest that residential development is playing a central role in this increasing sensitivity to suburban drought, though other factors are also important. Long-term planning and integration of land-use planning and water management emerged as two key paths for attenuating the impacts of development.