A ten channel fibre-optic device for distributed sensing of underground hydrocarbon leakage

With millions of fuel storage tanks and oil pipelines installed around the world, there is inevitably frequent leakage of potentially hazardous hydrocarbons. As many of these installations are below ground, it can often be many years before the extent of the leak is discovered. We have previously reported the development of a sensor for the detection of such subterranean leaks, using infrared reflectometry to interrogate a hydrocarbon sensitive membrane. However, a single sensor cannot provide any information about the flow rate or direction of the leak. This paper describes the extension of the technology to a multi-channel distributed sensing system, using optical fibres capable of distributing the sensors over large subterranean areas. Results are reported from the evaluation of the device, which consisted of monitoring the movement of different hydrocarbons (gasoline, diesel and insulating oil) through a vertical sand-filled vessel.     

A critical review of building environmental assessment tools

Since the field of environmental assessment tools for buildings is vast, the aim of this study is to clarify that field by analysing and categorising existing tools. The differences between the tools are discussed and the current situation within the tools is critically analysed. However, the comparison of the tools is difficult, if not impossible. For example, the tools are designed for assessing different types of buildings, and they emphasise different phases of the life cycle. In addition to environmental aspects, sustainable building includes economic and social aspects. The shift from green building to sustainable building and the future requirements are challenging for building environmental assessment tools. Furthermore, the benefits of using the tools should be analysed — how the tools and their results have affected decision making?     

A critical review of seven selected neighborhood sustainability assessment tools

Neighborhood sustainability assessment tools have become widespread since the turn of 21st century and many communities, mainly in the developed world, are utilizing these tools to measure their success in approaching sustainable development goals. In this study, seven tools from Australia, Europe, Japan, and the United States are selected and analyzed with the aim of providing insights into the current situations; highlighting the strengths, weaknesses, successes, and failures; and making recommendations for future improvements. Using a content analysis, the issues of sustainability coverage, pre-requisites, local adaptability, scoring and weighting, participation, reporting, and applicability are discussed in this paper. The results of this study indicate that most of the tools are not doing well regarding the coverage of social, economic, and institutional aspects of sustainability; there are ambiguities and shortcomings in the weighting, scoring, and rating; in most cases, there is no mechanism for local adaptability and participation; and, only those tools which are embedded within the broader planning framework are doing well with regard to applicability.     

The SITES reserve selection system: A critical review

Numerous models have been put forth to help with the growing demand for the establishment of biodiversity reserves. One site selection model that has been used in several recent studies is SITES [S.J. Andelman, I. Ball, F.W. Davis and D.M. Stoms, SITES V 1.0: an analytical toolbox for designing ecoregional conservation portfolios, Unpublished manual prepared for the nature conservancy, 1999, 1–43. (available at )]. SITES includes two heuristic solvers: based on Greedy and Simulated Annealing. We discuss the formulation of the SITES model, present a new formulation for that problem, and solve a number of test problems optimally using off-the-shelf software. We compared our optimal results with the SITES Simulated Annealing heuristic and found that SITES frequently returns significantly suboptimal solutions. Our results add further support to the argument, started by Underhill [L.G. Underhill, Optimal and suboptimal reserve selection algorithms, Biol. Conserv. 70 (1994) 85–87], continuing through Rodrigues and Gaston [A.S.L. Rodrigues and K.J. Gaston, Optimization in reserve selection procedures – why not?, Biol. Conserv. 107 (2002) 123–129], for greater integration of optimal methods in the reserve design/selection literature.     

Reforming EIA systems: A critical review of proposals in Brazil

Environmental Impact Assessment (EIA) systems are under pressure in many countries, driven by a call for efficiency and streamlining. Such a phenomenon is particularly clear in Brazil, where, in the past few years, a number of influential associations put forward documents proposing significant changes to environmental licensing and impact assessment regulations. So far, there is no publicly available information about any initiative towards scrutinizing those proposals. The objective of this study was to critically review the merits and drawbacks of the changes proposed in those documents. The analysis triangulated content analysis, focus group and online survey data. The focus group included ten seasoned Brazilian EIA specialists; the survey, based on Likert-scale and open-ended questions, resulted in 322 valid responses from EIA professionals. Results show that the proposals generally agree that the current EIA system, while playing a key role in mitigating impacts and enhancing project design, needs many changes. Nonetheless, the proposals neither offered solutions to overcome political, technical and budget barriers, nor established a sense of priority of the most urgent issues. Findings from the focus group and the survey signaled that a number of proposed actions might face public outcry, and that those changes that do not depend on legislative action are more likely to be implementable. Previous studies about EIA reform focused mostly on the context of developed countries after changes had taken place. This study, while addressing the perspective of a large developing country in a “before-reform” stage, shows that capacity-building is a key requirement in EIA reform.     

Impacts and mitigation measures of plastic waste: A critical review

Overwhelmed plastic waste has been gradually appreciated as a global problematic issue. Scientific efforts either dedicated to comprehending its distribution and detrimental impacts on the environment or management measures to contain it. However, there is a concern asymmetry between the knowledge of detrimental impacts of plastic waste and corresponding mitigation measures. Microplastics in the marine ecosystem is the foremost research hotspot in terms of plastic waste's detrimental impacts. Recycling plastic waste is the utmost research topic in terms of plastic waste management. Plastic pollutants derived from plastic waste contaminates the environment and ultimately threatens human health. Current measures aimed at reducing the plastic waste ended in the environment via recycling, and emphasised its retention of material value via circular economy. However, these measures did not prioritise taking direct action to mitigate the threats to human health. This review aims to bridge these two research ends of plastic waste that provides a holistic view of this problematic issue.The keywords analysis function in VOSviewer is adopted in this study to map out the state-of-the-art of existing research in plastic waste. Four research mainstreams are highlighted: (1) Environmental concerns of plastic waste in aquatic ecosystems; (2) Potential threats to human health; (3) Plastic waste reduction options and recycling methods; (4) Plastic waste thermochemical treatment. Consequently, a future research agenda is proposed.     

Economic models for climate policy analysis: A critical discussion

Climate policy analysis has come to rely heavily on large‐scale numerical simulation models of increasing complexity, posing a challenge to policy‐makers and other non‐specialists who must interpret and apply the models. This paper provides a “user's guide” to economic models used in climate analysis. We review basic features, underlying design issues, and basic research questions bearing on the models' foundations. We also provide an overview of five such global or world models currently in use.     

The determination of chlorofluorocarbons and extractives in the expanded and disposable polystyrene ware

Residual chlorofluorocarbons (CFCs) and water-extractive residues in expanded polystyrene ware were determined because of the threat to environmental and public health arising from the ozone depleting potential of CFCs and the leaching of toxic monomers and oligomers into food and drink. Chlorofluorocarbon in expanded polystyrene ware was analysed using headspace gas chromatography in the flame ionization mode, and confirmed by gas chromatography-mass spectrometry. The amount of extractive residue leached from this type of polymeric material was determined using an aqueous medium simulating categories of food and beverages. A wide range of concentrations of CFC-12 (dichlorodifluorocarbon) was detected in the styrofoam ware. It fluctuated between a low of 32 ppm and a high of 35471 ppm in two different samples of styrofoam plates. Similarly, the highest and lowest levels of extractive residue detected in two different styrofoam plates were 54 ppm and 0.5 ppm respectively. CFC-22 or HCFC (chlorodifluorocarbon) was absent from these expanded polystyrene ware. The continued use of chlorofluorocarbons as a blowing agent will further exert a deleterious effect on the stratospheric ozone layer. Though the level of water extractive residue from these expanded polystyrene ware was relatively safe, public health could be further safe-guarded through improvmeents in raw material selection and mode of production.     

A critical review of principal traffic noise models: Strategies and implications

The paper presents an exhaustive comparison of principal traffic noise models adopted in recent years in developed nations. The comparison is drawn on the basis of technical attributes including source modelling and sound propagation algorithms. Although the characterization of source in terms of rolling and propulsion noise in conjunction with advanced numerical methods for sound propagation has significantly reduced the uncertainty in traffic noise predictions, the approach followed is quite complex and requires specialized mathematical skills for predictions which is sometimes quite cumbersome for town planners. Also, it is sometimes difficult to follow the best approach when a variety of solutions have been proposed. This paper critically reviews all these aspects pertaining to the recent models developed and adapted in some countries and also discusses the strategies followed and implications of these models.     

Charcoal versus LPG grilling: A carbon-footprint comparison

Undoubtedly, grilling is popular. Britons fire up their barbeques some 60 million times a year, consuming many thousands of tonnes of fuel. In milder climates consumption is even higher, and in the developing world, charcoal continues to be an essential cooking fuel. So it is worth comparing the carbon footprints of the two major grill types, charcoal and LPG, and that was the purpose of the study this paper documents. Charcoal and LPG grill systems were defined, and their carbon footprints were calculated for a base case and for some plausible variations to that base case. In the base case, the charcoal grilling footprint of 998 kg CO₂e is almost three times as large as that for LPG grilling, 349 kg CO₂e. The relationship is robust under all plausible sensitivities. The overwhelming factors are that as a fuel, LPG is dramatically more efficient than charcoal in its production and considerably more efficient in cooking. Secondary factors are: use of firelighters, which LPG does not need; LPG's use of a heavier, more complicated grill; and LPG's use of cylinders that charcoal does not need.     

A comparison of fixed-site and non-fixed-site approaches for species protection

The efficacy of simultaneously advancing two distinct conceptual designs (referred to here as fixed-site and non-fixed-site) for species conservation and protection is addressed. In the literature, numerous models can be found that typically stem from a particular design, but rarely are comparisons made between approaches. This paper presents a more integrated optimization framework that models landowner behavior and species viabilities at a landscape scale. Regional demand for resource extraction is used as the economic driver, a variant of simulated annealing is used to solve the model under different species protection approaches, and a detailed species population simulator is utilized to measure biological responses. When directly comparing the outcomes of different species protection strategies from a case study in Oregon (USA), it was found that neither approach was universally superior in terms of financial value or degree of protection for two late seral forest dependent species.     

A critical analysis of sustainable micro-manufacturing from the perspective of the triple bottom line: A social network analysis

Nowadays, substantial improvements in sustainable micro-manufacturing are explicitly addressed based on the triple bottom line (TBL) concept. However, strong criticisms are leveled for the applications of TBL as immense complexities of inner relationships of items and dimensional relationships within TBL, which they cause an inefficacy of accessing critical information in introducing the TBL concept to sustainable micro-manufacturing. In this study, social network analysis (SNA) is used for developing a TBL network of sustainable micro-manufacturing to find out precise meanings of individual items of various dimensions of TBL and the relationships between them. The main metrics of the dominant items of TBL such as in-degree, out-degree, betweenness centrality and closeness centrality are detailly discussed with 16 nodes for three dimensions in the TBL networks. The related findings are further analyzed to reveal the current situation, technical gaps and chances for the sustainable development of the micro-manufacturing sector. This study aims to reveal the relationship between the items of TBL of micro-manufacturing, and delivers the significant roles of the items of TBL according to the findings of metrics and visual analyses for sustainable micro-manufacturing, supporting micro-manufacturing sectors to implement effective sustainable strategies for production activities.     

A comparison of nutrient losses from two simulated pastureland management scenarios

Fecal deposits by grazing animals on pasturelands have the potential to leach nutrients to runoff during rainfall events. Unlike croplands, grazing systems such as pasturelands or rangelands have little opportunity to ameliorate nutrient runoff through in-field or edge-of-field management practices. Thus, we investigated the amounts and concentrations of nutrients in overland flow from simulated grazing lands. Two grazing management scenarios were simulated: continuous grazing represented by two sparsely vegetated (SV) plots and rotational grazing represented by two densely vegetated (DV) plots. In addition, there were two control plots. The plots were treated with standard cowpats and rainfall was simulated until overland flow at the edge of the plots reached steady-state. Higher runoff was observed from DV plots (9.97 mm) than SV plots (7.05 mm), but the average total suspended solids concentration in runoff from SV plots was approximately 17 times the concentration observed in runoff from the DV plots. The average total phosphorus (TP) concentrations were highest in plots simulating continuous grazing (5.91 mg L(-1)). In both DV and SV plots at least 83% of the TP was found to be in the dissolved form. The average total Kjeldhal nitrogen (TKN) and total nitrogen concentrations observed in runoff samples from SV plots were 1.25 and 1.46 mg L(-1), respectively. Organic nitrogen comprised 95% of the TKN observed in runoff samples from SV plots. The SV plots have relatively higher loads for those nutrients in the particle associated form compared to DV plots, whereas DV plots had higher loads for those nutrients in the dissolved form. Grazing lands without any additional manure applications were found to release nutrients in high levels and vegetation did not show any effect on removing dissolved nutrients from runoff. These results are useful to inform selection of appropriate management practices to reduce nutrient transport to surface waters in watersheds dominated by grazed lands.     

A comparison of methods and materials for the analysis of leaded wipes

The purposes of this study are: (1) to determine whether proficiency analytical test (PAT) materials from the American Industrial Hygiene Association can be used to provide quality data for portable X-ray fluorescence analysis (XRF) of lead in dust wipe surface samples; (2) to provide data to determine whether the on-site analysis of field dust wipe samples by XRF and the laboratory method of inductively coupled plasma emission analysis (ICP) are comparable; and (3) to determine if differences exist between different wipe materials. Several wipes meet the ASTM E1792 performance requirements of lead background level less than 5 microg per wipe, be only one layer thick, yield recovery rates of 80- 120% from spiked samples, remain damp throughout the sampling procedure, and do not contain aloe. The wipes used in this study were Pace Wipes, which are used for the PAT materials, and, for the field samples, Palintest Wipes, which were supplied by the instrument manufacturer, and Ghost Wipes, which are popular because they digest in hot, concentrated acid, so that chemical analysis is simplified. Twenty PAT wipe samples were obtained from four different proficiency test rounds. Surface wipe samples were taken at three different locations representing different industry types. All samples were analyzed using a portable XRF spectrometer and by ICP. Strong linear relationships were found for the analysis of wipe samples by ICP and by portable XRF. For the PAT samples, the results from the ICP and XRF analysis were not statistically equivalent, which indicates a bias in the ICP analysis. The bias was not excessive, since all ICP analyses fell within the acceptable range for the proficiency samples. The good correlation between the proficiency sample reference values and the XRF determinations is not surprising considering similar proficiency samples were used to calibrate the instrument response. Users of this portable XRF analyzer could enroll in the proficiency test program as part of their quality assurance program. For field samples, the relationship was strongest for Palintest wipes, and the values found for all three industries could be combined. However, the results from the ICP and XRF analysis were not statistically equivalent using the correction factor in the calculation algorithm as supplied with the instrument, and a new coefficient was derived. The mean relative error for the XRF analysis versus the ICP analysis was greater than 25%, such that the method falls within the realm of screening procedures. For Ghost Wipe samples, the precision was different for different industries, and the results could not be pooled. Differences between the two wipe materials may be related to the number of folds required for analysis.     

Sami-state collaboration in the governance of cumulative effects assessment: A critical action research approach

Indigenous-state collaboration in the governance of cumulative effects assessment (CEA) is often hampered not only by legacies of colonialism and inequality but also disagreement on what the ‘CEA governance problem’ is in the first place. In this paper, we draw on critical theories on dialogue and collaboration to present a novel approach to joint problem analysis between Sami reindeer herders and civil servants in Swedish permitting authorities on mining, wind energy and forestry. We discuss process design choices, insights on CEA governance and ways to tackle these barriers in practice. We argue that indigenous-state collaboration may play a constructive role in improving CEA governance, including the recognition of indigenous peoples' rights. However, this requires a process that carves out new spaces for exploring divergent problem definitions and supports the participants in challenging institutionalized inequalities within their positioned realities.     

A comparison of data quality control protocols for atmospheric mercury speciation measurements

Significant advances in the measurement of atmospheric mercury species have been made in the past 10 years yet limited protocols on quality control (QC) and assurance on this data have been published in the literature. Recently, considerable work has been done to develop quality control and assurance programs within North America. Environment Canada and the National Atmospheric Deposition Network (NADP) independently developed programs, RDMQ? and AMQC, respectively, to QC atmospheric mercury speciation data (including gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and mercury associated to particles (PHg)). These 2 programs were assessed by the criteria on which the data is QCed and comparability of the final data products. Results show that the criteria used to flag data compare well within the 4 tested sites and that the number of flags for each criterion is generally comparable. The QC programs were applied to 2 distinct data sets and the final QCed data was compared. From a mid-latitude site, the final data sets compare very well and showed there to be a 0.3, 8.6 and 15% difference in the mean GEM, RGM and PHg concentrations post QC of each program. It is recommended that either the RDMQ or the AMQC programs be employed for a typical mid-latitude site. When the QC programs were applied to highly variable data, the data do not compare as well for RGM and PHg. Results showed a 2.7, 27 and 33% difference in the mean GEM, RGM and PHg concentrations, respectively, post QC of each program. It is recommended that RDMQ be used for data that is highly variable with high RGM/PHg concentrations as it allows for more manual correction over the QCed data. This investigation of 2 QC programs produced comparable data and that either of these programs can be used as standard methods for the quality control of atmospheric mercury speciation data.     

A ten year summary of concurrent ambient water column and sediment toxicity tests in the Chesapeake Bay watershed: 1990-1999

The goal of this study was to identify the relative toxicity ofambient areas in the Chesapeake Bay watershed by using a suiteof concurrent water column and sediment toxicity tests at seventy-five ambient stations in 20 Chesapeake Bay rivers from1990 through 1999. Spatial and temporal variability was examinedat selected locations throughout the 10 yr study. Inorganicand organic contaminants were evaluated in ambient water andsediment concurrently with water column and sediment tests toassess possible causes of toxicity although absolute causalitycan not be established. Multivariate statistical analysis wasused to develop a multiple endpoint toxicity index (TOX-INDEX) at each station for both water column and sediment toxicity data. Water column tests from the 10 yr testing period showed that49% of the time, some degree of toxicity was reported. The mosttoxic sites based on water column results were located inurbanized areas such as the Anacostia River, Elizabeth River andthe Middle River. Water quality criteria for copper, lead,mercury, nickel and zinc were exceeded at one or more of thesesites. Water column toxicity was also reported in localizedareas of the South and Chester Rivers. Both spatial and temporalvariability was reported from the suite of water column toxicitytests. Some degree of sediment toxicity was reported from 62% of the tests conducted during the ten year period. The ElizabethRiver and Baltimore Harbor stations were reported as the most toxic areas based on sediment results.Sediment toxicity guidelines were exceeded for one or more of thefollowing metals at these two locations: arsenic, cadmium,chromium, copper, lead, nickel and zinc. At the Elizabeth Riverstations nine of sixteen semi-volatile organics and two of sevenpesticides measured exceeded the ER-M values in 1990. Ambientsediment toxicity tests in the Elizabeth River in 1996 showedreduced toxicity. Various semi-volatile organics exceeded the ER-M values at a number of Baltimore Harbor sites; pyrene anddibenzo(a,h)anthracene were particularly high at one of thestations (Northwest Harbor). Localized sediment toxicity was alsoreported in the Chester, James, Magothy, Rappahannock, andPotomac Rivers but the link with contaminants was not determined.Both spatial and temporal variability was less for sedimenttoxicity data when compared with water column toxicity data. Acomparison of water column and sediment toxicity data for thevarious stations over the 10 yr study showed that approximatelyhalf the time agreement occurred (either both suite of testsshowed toxicity or neither suite of tests showed toxicity).     

A comparison of techniques to sample salamander assemblages along highland streams of Maryland

Amphibians may be useful indicators of biological condition in small streams so determining which sampling technique maximizes encounters at the least cost and at the optimal time of year is important. Area constrained surveys (ACS), used by the Maryland Biological Stream Survey, were tested against cover board surveys, drift fences with pitfall and funnel traps, quadrat leaf litter searches, and leaf litter bags. Sixteen, 100 m-long sites were established in headwater streams in the Savage River State Forest in Garrett County, Maryland. Each technique was randomly assigned to a 25 m stream section within each overall sampling site, and sites were sampled once each month from May to October (2005) with additional sampling in March and April (2006). Area constrained surveys yielded means of 2.7 taxa and 14.9 total individuals per sampling visit, which was significantly higher than the yield of all other methods in all months except October and March, when yields were low for all techniques. Area constrained surveys were also significantly more cost-effective per taxon and per individual compared to all other methods. September produced the most taxa and individuals, October and March produced the least, and yields for April through August were similar to September. We employed removal sampling at four sites in April 2006, but abundance could not be estimated because a significant linear decrease in the accumulated catch versus catch per unit effort did not occur for three of the sites.