Safety with access scaffolds: development of a prototype decision aid based on accident analysis

PROBLEM: Accidents involving temporary access systems, particularly temporary scaffolds, account for a large proportion of injuries in the construction industry worldwide. METHOD: This paper outlines the development of a prototype decision aid (SCAFPASS, an abbreviation for Scaffold Planning Aid for System Safety) to promote access scaffold safety. It was guided by an examination of the root-causes and management deficiencies apparent in: (a) paper-based files of 186 access-related incidents held by the Health and Safety Executive (HSE) in the UK; and (b) computer-based files of 2,910 incidents appearing in the HSE database between 1997 to 2000. RESULTS: The more frequent root-causes included the fitting of defective components, unauthorized modification of the structure, omission of barriers, and errors resulting in simple, readily detectable structural faults. Common managerial deficiencies included failure to control risk, unsafe methods and procedures, and inadequate training and supervision. IMPACT ON INDUSTRY: SCAFPASS aims to avoid these root-causes by improving safety management from the outset and throughout all phases of a project.     

A framework for the management of sand dune systems in Wales

The Countryside Council for Wales (CCW) is developing a management framework with the primary aim of restoring favourable conservation status to the sand dune resource of Wales. It will take onboard the requirements of both national and international conservation legislation and will also help CCW integrate its responsibilities for biodiversity, geodiversity, landscape, access and recreation for this habitat. In order to achieve certain conservation goals it will be necessary to have in place a variety of different types of management ranging from non- or minimal intervention through to intensive single species management and habitat re-creation. However, it will not provide a comprehensive framework for all aspects of site management, but only those that are deemed to be of strategic importance, and have significance within an all-Wales perspective for their nature conservation importance.     

Hydraulic performance of a proposed in situ photocatalytic reactor for degradation of MTBE in water

Methyl tert-butyl ether (MTBE) groundwater remediation projects often require a combination of technologies resulting in increasing the project costs. A cost-effective in situ photocatalytic reactor design, Honeycomb II, is proposed and tested for its efficiency in MTBE degradation at various flows. This study is an intermediate phase of the research in developing an in situ photocatalytic reactor for groundwater remediation. It examines the effect of the operating variables: air and water flow and double passages through Honeycomb II, on the MTBE removal. MTBE vaporisation is affected by not only temperature, Henry’s law constant and air flow to volume ratio but also reactor geometry. The column reactor achieved more than 84% MTBE removal after 8 h at flows equivalent to horizontal groundwater velocities slower than 21.2 cm d⁻¹. Despite the contrasting properties between a photocatalytic indicator methylene blue and MTBE, the reactor efficiency in degrading both compounds showed similar responses towards flow (equivalent groundwater velocity and hydraulic residence time (HRT)). The critical HRT for both compounds was approximately 1 d, which corresponded to a velocity of 21.2 cm d⁻¹. A double pass through both new and used catalysts achieved more than 95% MTBE removal after two passes in 48 h. It also verified that the removal efficiency can be estimated via the sequential order of the removal efficiency of one pass obtained in the laboratory. This study reinforces the potential of this reactor design for in situ groundwater remediation.     

Effects of seascape connectivity on reserve performance along exposed coastlines

Seascape connectivity (landscape connectivity in the sea) can modify reserve performance in low-energy marine ecosystems (e.g., coral reefs, mangroves, and seagrass), but it is not clear whether similar spatial linkages also shape reserve effectiveness on high-energy, exposed coastlines. We used the surf zones of ocean beaches in eastern Australia as a model system to test how seascape connectivity and reserve attributes combine to shape conservation outcomes. Spatial patterns in fish assemblages were measured using baited remote underwater video stations in 12 marine reserves and 15 fished beaches across 2000 km of exposed coastline. Reserve performance was shaped by both the characteristics of reserves and the spatial properties of the coastal seascapes in which reserves were embedded. Number of fish species and abundance of harvested fishes were highest in surf-zone reserves that encompassed >1.5 km of the surf zone; were located < 100 m to rocky headlands; and included pocket beaches in a heterogeneous seascape. Conservation outcomes for exposed coastlines may, therefore, be enhanced by prioritizing sufficiently large areas of seascapes that are strongly linked to abutting complementary habitats. Our findings have broader implications for coastal conservation planning. Empirical data to describe how the ecological features of high-energy shorelines influence conservation outcomes are lacking, and we suggest that seascape connectivity may have similar ecological effects on reserve performance on both sheltered and exposed coastlines.     

Road transport in drift? Applying contemporary systems thinking to road safety

Despite the extent to which the proximal causes of road traffic injury are known, road trauma remains a substantial and growing component of the global health burden. Application of contemporary sociotechnical systems theory to the problem of traffic injury suggests that the lack of progress globally may be a consequence of “drift into failure”. This article considers the new systems perspective on safety, explores the utility of this approach for road safety efforts, and specifically examines the ‘drift into failure’ hypothesis. It is argued that road transport systems do currently display characteristics of complex systems in drift and that greater understanding of complexity theory-based models will support improved road safety efforts. However, the extent to which such models can support road safety practitioners appears to be limited by the lack of practical tools for translating theory to practice. The article concludes by drawing attention to similarities between complex systems theory and the contexts in which the discipline of Human Factors has been developed, and suggests that Human Factors methodologies could be usefully used to facilitate further research in this field.     

Contaminants in water, sediment and fish biomonitor species from natural and artificial estuarine habitats along the urbanized Gold Coast, Queensland

Metal and pesticide contaminants were measured in water, sediment and fish species in various Gold Coast waterways, Queensland. With the exception of Cu, metal concentrations in water, measured using the diffuse gradients in a thin film (DGT) technique, complied with relevant Australian guidelines. Cu concentrations in these waterways have been related to recreational vessel activities previously. All sediment metal concentrations measured were below the national guidelines, although Cu, Zn and Pb were found to vary significantly between habitat types. Evidence of spikes in sediment pesticide concentrations (some banned over 50 years ago) was observed in some artificial residential waterways. Heavy metals and pesticides were measured in the tissue (muscle, gills and liver) of three economically important species of fish, with different feeding strategies (partly herbivore Arrhamphus sclerolepis, carnivore Acanthopagrus australis, detritivore Mugil cephalus). We tested the hypothesis that fish accumulate different amounts of contaminants from wetland habitats affected by different intensities of anthropogenic activities (i.e., marinas, artificial residential canals, artificial residential lakes, estuaries and natural, vegetated waterways). Significantly higher concentrations of Cu were found in the gills of each fish species from marinas compared to fish caught in other waterways. Furthermore, fish caught in canals had the second highest Cu and natural waterways the lowest. These results support the stated hypothesis for Cu and furthermore indicate that these fish species are suitable as biomonitors in estuarine waterways. Metal and pesticide concentrations in the edible muscle tissue of all fish complied with the Australian Food Standard Code recommended limits for human consumption, apart from As which is likely to be due to bioconcentration of lower toxicity organo-As species. These results indicate a low health risk for humans consuming fish, in terms of contaminant levels. The accumulated body of evidence on contaminants within Gold Coast waterways generally suggests that there are no major threats of metal or pesticide contamination, except for marina facilities which are a major source of Cu which also accumulates in fish. Water quality threats are also highlighted in residential canals, presumably as a consequence of their hydrological design.     

Modelling mixing height from routinely measured surface and upper air meteorological data

A one‐dimensional model is developed for the estimation of hourly mixing height values from routinely measured upper air and surface meteorological data. A diagnostic technique is used in the model to calculate the convective and mechanically induced mixing height values under different atmospheric, and day and night‐time conditions. In the scheme, for the day‐time hours, the mixing height is determined as the larger of the convective and mechanically induced mixing height values. For the night‐time hours, only the mechanically induced mixing height values are considered. Three‐hourly mixing height values are modelled using once‐a‐day upper air temperature profile data (from radio‐sonde) and three‐hourly surface meteorological data. The spatial and temporal variation of mixing height are modelled in the Brisbane airshed and their relationship with the atmospheric stability, solar radiation and transport wind speed is developed.     

URBAN SERVICE PRICING AND LAND USE: SOME PRELIMINARY RESULTS1

ABSTRACT The use of public policy variables to control urban land use has been suggested or implied by a number of authors. This paper presents a conceptual foundation for doing so and the results of some empirical analyses based on this conceptual foundation. The method developed appears to constitute an alternative to more expensive approaches to the analysis of the relation between policy variables and land use. The empirical results tend to support earlier suggestions advanced by other researchers.     

Photocatalytic degradation of aqueous methyl-tert-butyl-ether (MTBE) in a supported-catalyst reactor

Contamination of groundwater by methyl-tert-butyl ether (MTBE) poses increasing problems to water companies. Here we demonstrate the feasibility of using a cylindrical, supported-catalyst reactor for photocatalytic degradation of MTBE in water. It was shown that photocatalytic degradation of MTBE follows pseudo first-order kinetics. The maximum reaction rate constant observed was 0.47 hr^–1. The reaction rate increases linearly with increasing light intensity. It was also found that the reaction rate is linearly proportional to the ratio of catalyst surface area to volume of reactor. Complete degradation of MTBE was reached with an excess supply of oxygen.