Progress in sustainability science: lessons learnt from current methodologies for sustainability assessment: Part 1

Purpose

Sustainability Science (SS) is considered an emerging discipline, applicative and solution-oriented whose aim is to handle environmental, social and economic issues in light of cultural, historic and institutional perspectives. The challenges of the discipline are not only related to better identifying the problems affecting sustainability but to the actual transition towards solutions adopting an integrated, comprehensive and participatory approach. This requires the definition of a common scientific paradigm in which integration and interaction amongst sectorial disciplines is of paramount relevance. In this context, life cycle thinking (LCT) and, in particular, life cycle-based methodologies and life cycle sustainability assessment (LCSA) may play a crucial role. The paper illustrates the main challenges posed to sustainability assessment methodologies and related methods in terms of ontology, epistemology and methodology of SS. The aims of the analysis are twofold: (1) to identify the main features of methodologies for sustainability assessment and (2) to present key aspects for the development of robust and comprehensive sustainability assessment.

Methods

The current debate on SS addressing ontological, epistemological and methodological aspects has been reviewed, leading to the proposal of a conceptual framework for SS. In addition, a meta-review of recent studies on sustainability assessment methodologies and methods, focusing those life cycle based, supports the discussion on the main challenges for a comprehensive and robust approach to sustainability assessment. Starting from the results of the meta-review, we identified specific features of sustainable development-oriented methods: firstly, highlighting key issues towards robust methods for SS and, secondly, capitalising on the findings of each review’s paper. For each issue, a recommendation towards a robust sustainability assessment method is given. Existing limitations of sectorial academic inquiries and proposal for better integration and mainstreaming of SS are the key points under discussion.

Discussion

In the reviewed papers, LCT and its basic principles are acknowledged as relevant for sustainability assessment. Nevertheless, LCT is not considered as a reference approach in which other methods could also find a place. This aspect has to be further explored, addressing the lack of multi-disciplinary exchange and putting the mainstreaming of LCT as a priority on the agenda of both life cycle assessment and sustainability assessment experts. Crucial issues for further developing sustainability assessment methodologies and methods have been identified and can be summarised as follows: holistic and system wide approaches, shift from multi- towards trans-disciplinarity; multi-scale (temporal and geographical) perspectives; and better involvement and participation of stakeholders.

Conclusions

Those are also the main challenges posed to LCSA in terms of progress of ontology, epistemology and methodology in line with the progress of SS. The life cycle-based methodologies should be broadened from comparing alternatives and avoiding negative impacts, to also proactively enhancing positive impacts, and towards the achievement of sustainability goals.     

Review of criteria for evaluating LCA weighting methods

Purpose

In the process of selecting where effective environmental measures should be directed, the weighting step of life cycle assessment (LCA) is an optional, controversial, but nevertheless important tool. A set of criteria for evaluating weighting methods has relevance in the process of acquiring meta-knowledge, and thus competence, in assigning relative weights to environmental impact categories. This competence is helpful when choosing between presently available weighting methods, and in creating new weighting methods.

Methods

Criteria in LCA-related literature are reviewed. The authors have focused on identifying lists of criteria rather than extracting criteria from bulks of text. An important starting point has been the actual use of the term “criterion”, while at the same time disqualifying certain definitions of the term which are too far removed from the two definitions provided in this article.

Results and discussion

Criteria for evaluating weighting methods are shown to fall into two general categories. The first being general criteria for weighting methods, demanding that weighting methods have a broad scope, are practical for users and scientists, are scientific and have ethical goals. The second being criteria proposing characteristics of concrete environmental damage which should be taken into account by a weighting method. A noteworthy example is reversibility.

Conclusions

While the comprehensive tables of criteria speak for themselves, it can be observed that the need for transparency is particularly highlighted in literature. Furthermore, ISO 14044’s statement that the weighting step is “not scientifically based” would appear to defy a significant proportion of the other criteria reviewed; this, however, depends on its interpretation.     

The search for an appropriate end-of-life formula for the purpose of the European Commission Environmental Footprint initiative

Purpose

This paper explains in details the rationale behind the choice of the end-of-life allocation approach in the European Commission Product Environmental Footprint (PEF) and Organisational Environmental Footprint (OEF) methods. The end-of-life allocation formula in the PEF/OEF methods aims at enabling the assessment of all end-of-life scenarios possible, including recycling, reuse, incineration (with heat recovery) and disposal for both open- and closed-loop systems in a consistent and reproducible way. It presents how the formula builds on existing standards and how and why it deviates from them.

Methods

Various end-of-life allocation approaches and formulas, mainly taken not only from/based on existing environmental impact assessment methods and/or standards but also one original linearly degressive approach, were analysed against a predetermined set of criteria, reflecting the overall aim of the PEF/OEF methods. This set of criteria is physical realism, distribution of burdens and benefits in a product cascade system and applicability. Besides the qualitative analysis, the various formulas were implemented for several products and for different scenarios regarding recycled content and recyclability to check the robustness of the outcomes, exemplary expressed for the Global Warming Potential impact category.

Results and discussion

As reaching physical realism was impossible at both the product and overall product cascade system level by any of the end-of-life approaches analysed, one of both had to be prioritised. The paper explains in details why a product level approach was preferred in the context of the PEF/OEF methods. In consequence, allocation of the end-of-life processes which are related to more than one product in a product cascade system is needed and should be carefully considered as it has a major influence on the results and decision taking.

Conclusions

A formula taking into account the number of recycling cycles of a material was identified as preferred to reach physical realism and to allocate burdens and benefits of repeatedly recycling of a material over the different products in a product cascade system. However, this approach was not selected for the PEF/OEF methods as data on the number of recycling cycles was insufficiently available (for the time being) for all products on the market and hence fails the criterion of “applicability”. This explains why, instead, a formula based on the 50:50 approach—allocating shared end-of-life processes equally between the previous and subsequent product—was selected for the PEF/OEF methods.

     

A review of life cycle assessments on wind energy systems

Purpose

Several life cycle assessments (LCAs) of wind energy published in recent years are reviewed to identify methodological differences and underlying assumptions.

Methods

A full comparative analysis of 12 studies were undertaken (ten peer-reviewed papers, one conference paper, and one industry report) regarding six fundamental factors (methods used, energy use accounting, quantification of energy production, energy performance and primary energy, natural resources, and recycling). Each factor is discussed in detail to highlight strengths and shortcomings of various approaches.

Results

Several potential issues are found concerning the way LCA methods are used for assessing energy performance and environmental impact of wind energy, as well as dealing with natural resource use and depletion. The potential to evaluate natural resource use and depletion impacts from wind energy appears to be poorly exploited or elaborated on in the reviewed studies. Estimations of energy performance and environmental impacts are critically analyzed and found to differ significantly.

Conclusions and recommendations

A continued discussion and development of LCA methodology for wind energy and other energy resources are encouraged. Efforts should be made to standardize methods and calculations. Inconsistent use of terminology and concepts among the analyzed studies are found and should be remedied. Different methods are generally used and the results are presented in diverse ways, making it difficult to compare studies with each other, but also with other renewable energy sources.     

Sensitivity analysis of methodological choices in road pavement LCA

Purpose

There are methodological questions concerning life cycle assessment (LCA) and carbon footprint evaluation of road pavements, including allocation among co-products or at end-of-life (EOL) recycling. While the development and adoption of a standard methodology for road pavement LCA would assist in transparency and decision making, the impact of the chosen method on the results has not yet been fully explored.

Methods

This paper examines the methodological choices made in UK PAS 2050 and asphalt Pavement Embodied Carbon Tool (asPECT), and reviews the allocation methods available to conduct road pavement LCA. A case study of a UK inter-urban road construction (cradle-to-laid) is presented to indicate the impact of allocation amongst co-products (bitumen and blast furnace slag); a typical UK asphalt production (cradle-to-gate) is modelled to show the influence of allocation at EOL recycling.

Results and discussion

Allocation based on mass is found to consistently lead to the highest figures in all impact categories, believed to be typical for construction materials. Changing from industry chosen allocation methods (Eurobitume, asPECT) to 100 % mass or economic allocation leads to changes in results, which vary across impact categories. This study illustrates how the allocation methods for EOL recycling affect the inventory of a unit process (asphalt production).

Conclusions and recommendations

Sensitivity analysis helps to understand the impact of chosen allocation method and boundary setting on LCA results. This initial work suggests that economic allocation to co-products used as secondary pavement materials may be more appropriate than mass allocation. Allocation at EOL recycling by a substitution method may remain most appropriate, even where the balance of credits between producers and users may be hampered by an inability to confidently predict future recycling rates and methods. In developing sector-specific guidelines, further sensitivity checks are recommended, such as for alternative materials and traffic management during maintenance.     

Methods for the guideline-based development of quality indicators--a systematic review

Background

Quality indicators (QIs) are used in many healthcare settings to measure, compare, and improve quality of care. For the efficient development of high-quality QIs, rigorous, approved, and evidence-based development methods are needed. Clinical practice guidelines are a suitable source to derive QIs from, but no gold standard for guideline-based QI development exists. This review aims to identify, describe, and compare methodological approaches to guideline-based QI development.

Methods

We systematically searched medical literature databases (Medline, EMBASE, and CINAHL) and grey literature. Two researchers selected publications reporting methodological approaches to guideline-based QI development. In order to describe and compare methodological approaches used in these publications, we extracted detailed information on common steps of guideline-based QI development (topic selection, guideline selection, extraction of recommendations, QI selection, practice test, and implementation) to predesigned extraction tables.

Results

From 8,697 hits in the database search and several grey literature documents, we selected 48 relevant references. The studies were of heterogeneous type and quality. We found no randomized controlled trial or other studies comparing the ability of different methodological approaches to guideline-based development to generate high-quality QIs. The relevant publications featured a wide variety of methodological approaches to guideline-based QI development, especially regarding guideline selection and extraction of recommendations. Only a few studies reported patient involvement.

Conclusions

Further research is needed to determine which elements of the methodological approaches identified, described, and compared in this review are best suited to constitute a gold standard for guideline-based QI development. For this research, we provide a comprehensive groundwork.     

The quality of reporting of RCTs used within a postoperative pain management meta-analysis, using the CONSORT statement

Background

Randomized controlled trials (RCTs) are routinely used in systematic reviews and meta-analyses that help inform healthcare and policy decision making. The proper reporting of RCTs is important because it acts as a proxy for health care providers and researchers to appraise the quality of the methodology, conduct and analysis of an RCT. The aims of this study are to analyse the overall quality of reporting in 23 RCTs that were used in a meta-analysis by assessing 3 key methodological items, and to determine factors associated with high quality of reporting. It is hypothesized that studies with larger sample sizes, that have funding reported, that are published in journals with a higher impact factor and that are in journals that have adopted or endorsed the CONSORT statement will be associated with better overall quality of reporting and reporting of key methodological items.

Methods

We systematically reviewed RCTs used within an anesthesiology related post-operative pain management meta-analysis. We included all of the 23 RCTs used, all of which were parallel design that addressed the use of femoral nerve block in improving outcomes after total knee arthroplasty. Data abstraction was done independently by two reviewers. The two main outcomes were: 1) 15 point overall quality of reporting score (OQRS) based on the Consolidated Standards for Reporting Trials (CONSORT) and 2) 3 point key methodological item score (KMIS) based on allocation concealment, blinding and intention-to-treat analysis.

Results

Twenty-three RCTs were included. The median OQRS was 9.0 (Interquartile Range?=?3). A multivariable regression analysis did not show any significant association between OQRS or KMIS and our four predictor variables hypothesized to improve reporting. The direction and magnitude of our results when compared to similar studies suggest that the sample size and impact factor are associated with improved key methodological item reporting.

Conclusions

The quality of reporting of RCTs used within an anesthesia related meta-analysis is poor to moderate. The information gained from this study should be used by journals to register the urgency for RCTs to be clear and transparent in reporting to help make literature accessible and comparable.     

Quantifying anthropogenic mobilization,flows (in product systems) and emissions of fixed nitrogen in process-based environmental life cycle assessment: rationale,methods and application to a life cycle inventory

Purpose

Anthropogenic perturbation of the nitrogen cycle is attracting increasing attention as both an environmental and societal concern. Here, we provide the rationale and propose methods for independent treatment of anthropogenic mobilization, flows (in product systems) and emissions of fixed nitrogen in process-based environmental life cycle assessment.

Methods

We propose a simple methodology for aggregating N flows in life cycle assessment (LCA), with supporting characterization factors for all nitrogen-containing compounds on the Organization for Economic Cooperation and Development High Production Volume Chemical List for which specific chemical formulae are available, as well as all nitrogen-containing flows in the International Reference Life Cycle Data System. We subsequently apply our method and characterization factors to a life cycle inventory data set representing a subset of the consumption attributable to an average EU-27 consumer and compare the results against previously published estimates for nitrogen emissions at the consumer level that were generated using alternative methods/approaches.

Results and discussion

We derive a suite of over 2,000 characterization factors for nitrogen-containing compounds. Overall, the results generated by applying our method and characterization factors to the European Commission Basket-of-Products life cycle inventory data set are consistent with those observed from studies having a similar scope but different methodological approach.

Conclusions

This outcome suggests that anthropogenic mobilization, flows (in product systems) and emissions of fixed nitrogen can, indeed, be systematically inventoried and aggregated in process-based LCA for the purpose of better understanding and managing anthropogenic impacts on the global nitrogen cycle using the methods and characterization factors we propose.     

Effectiveness of complete conservative treatment for adolescent idiopathic scoliosis (bracing and exercises) based on SOSORT management criteria: results according to the SRS criteria for bracing studies - SOSORT Award 2009 Winner

Background

The SRS criteria give the methodological reference framework for the presentation of bracing results, while the SOSORT criteria give the clinical reference framework for an appropriate bracing treatment. The two have not been combined in a study until now. Our aim was to verify the efficacy of a complete, conservative treatment of Adolescent Idiopathic Scoliosis (AIS)according to the best methodological and management criteria defined in the literature.

Methods

Study Design. Retrospective study. Population. We included all AIS patients respecting the SRS inclusion criteria (age 10 years or older; Risser test 0-2; Cobb degrees 25-40°; no prior treatment; less than one year post-menarchal) who had reached the end of treatment since our institute database start in 2003. Thus we had 44 females and four males, with an age of 12.8 ± 1.6 at the commencement of the study. Methods. According to individual needs, two patients have been treated with Risser casts followed by Lyon brace, 40 with Lyon or SPoRT braces (14 for 23 hours per day, 23 for 21 h/d, and seven for 18 h/d at start), and two with exercises only (1 male, 1 female): these were excluded from further analysis. Outcome criteria. SRS (unchanged; worsened 6° or more; over 45° at the end of treatment; surgically treated; two years' follow-up); clinical (ATR, Aesthetic Index, plumbline distances); radiographic (Cobb degrees); and ISICO (optimal; minimal). Statistics. Paired ANOVA and t-test, Tukey-Kramer and chi-square test.

Results

Median reported compliance during the 4.2 ± 1.4 treatment years was 90% (range 5-106%). No patient progressed beyond 45°, nor was any patient fused, and this remained true at the two-year follow-up for the 85% that reached it. Only two patients (4%) worsened, both with single thoracic curve, 25-30° Cobb and Risser 0 at the start. We found statistically significant reductions of the scoliosis curvatures (-7.1°): thoracic (-7.3°), thoracolumbar (-8.4°) and lumbar (-7.8°), but not double major. Statistically significant improvements have also been found for aesthetics and ATR.

Conclusion

Respecting also SOSORT management criteria and thus increasing compliance, the results of conservative treatment were much better than what had previously been reported in the literature using SRS criteria only.     

Exploring variability in methods and data sensitivity in carbon footprints of feed ingredients

Purpose

Production of feed is an important contributor to life cycle greenhouse gas emissions, or carbon footprints (CFPs), of livestock products. Consequences of methodological choices and data sensitivity on CFPs of feed ingredients were explored to improve comparison and interpretation of CFP studies. Methods and data for emissions from cultivation and processing, land use (LU), and land use change (LUC) were analyzed.

Method

For six ingredients (maize, wheat, palm kernel expeller, rapeseed meal, soybean meal, and beet pulp), CFPs resulting from a single change in methods and data were compared with a reference CFP, i.e., based on IPCC Tier 1 methods, and data from literature.

Results and discussion

Results show that using more detailed methods to compute N₂O emissions from cultivation hardly affected reference CFPs, except for methods to determine $ \mathrm{NO}_3^{-} $ leaching (contributing to indirect N₂O emissions) in which the influence is about ?7 to +12 %. Overall, CFPs appeared most sensitive to changes in crop yield and applied synthetic fertilizer N. The inclusion of LULUC emissions can change CFPs considerably, i.e., up to 877 %. The level of LUC emissions per feed ingredient highly depends on the method chosen, as well as on assumptions on area of LUC, C stock levels (mainly aboveground C and soil C), and amortization period.

Conclusions

We concluded that variability in methods and data can significantly affect CFPs of feed ingredients and hence CFPs of livestock products. Transparency in methods and data is therefore required. For harmonization, focus should be on methods to calculate $ \mathrm{NO}_3^{-} $ leaching and emissions from LULUC. It is important to consider LUC in CFP studies of food, feed, and bioenergy products.     

Parameterization in Life Cycle Assessment inventory data: review of current use and the representation of uncertainty

Purpose

Parameterization refers to the practice of presenting Life Cycle Assessment (LCA) data using raw data and formulas instead of computed numbers in unit process datasets within databases. This paper reviews parameterization methods in the European Reference Life Cycle Data System (ELCD), ecoinvent v3, and the US Department of Agriculture's Digital Commons with the intent of providing a basis for continued methodological and coding advances.

Methods

Parameterized data are reviewed and categorized with respect to the type (raw data and formulas) and what is being represented (e.g., consumption and emission rates and factors, physical or thermodynamic properties, process efficiencies, etc.). Parameterization of engineering relationships and uncertainty distributions using Smirnov transforms (a.k.a. inverse transform sampling), and ensuring uncertain individual fractions (e.g., market shares) sum to the total value of interest are presented.

Results

Seventeen categories of parameters (raw data and formulas) are identified. Thirteen ELCD unit process datasets use 975 parameters in 12 categories, with 124 as raw data points and 851 as formulas, and emission factors as the most common category of parameter. Five additional parameter categories are identified in the Digital Commons for the presentation and analysis of data with uncertainty information, through 146 parameters, of which 53 represent raw data and 93 are formulas with most being uncertainty parameters, percentages, and consumption parameters.

Conclusions

Parameterization is a powerful way to ensure transparency, usability, and transferability of LCI data. Its use is expected to increase in frequency, the categories of parameters used, and the types of computational methods employed.     

Does the Angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism modify the response to ACE inhibitor therapy? – A systematic review

Background

Pharmacogenetic testing to individualize ACE inhibitor therapy remains controversial. We conducted a systematic review to assess the effect modification of the insertion/deletion (I/D) polymorphism of the ACE gene on any outcome in patients treated with ACE inhibitors for cardiovascular and/or renal disease.

Methods

Our systematic review involved searching six electronic databases, then contacting the investigators (and pharmaceutical industry representatives) responsible for the creation of these databases. Two reviewers independently selected relevant randomized, placebo-controlled trials and abstracted from each study details on characteristics and quality.

Results

Eleven studies met our inclusion criteria. Despite repeated efforts to contact authors, only four of the eleven studies provided sufficient data to quantify the effect modification by genotypes. We observed a trend towards better response to ACE inhibitors in Caucasian DD carriers compared to II carriers, in terms of blood pressure, proteinuria, glomerular filtration rate, ACE activity and progression to end-stage renal failure. Pooling of the results was inappropriate, due to heterogeneity in ethnicity, clinical domains and outcomes.

Conclusion

Lack of sufficient genetic data from the reviewed studies precluded drawing any convincing conclusions. Better reporting of genetic data are needed to confirm our preliminary observations concerning better response to ACE inhibitors among Caucasian DD carriers as compared to II carriers.     

Estimating the absorptive root area in Norway spruce by using the common direct and indirect earth impedance methods

Aims

Estimates of root absorption magnitude are needed for the balanced management of forest ecosystems, but no methods able to work on the whole tree and stand level were available. Modified earth impedance method was developed recently and here it was tested, by comparing the results with those obtained by combination of several classical methods.

Methods

We used direct (soil cores, scanning and microscopy) and indirect (sap flow patterns and modified earth impedance) methods in an attempt to estimate the absorptive root area indexes (RAI) at two sites of about 25 and 40-years-old Norway spruce. We considered the geometric surfaces of all scanned fine roots to be equal to the fine root absorptive area (RAI _scan ). To estimate the potentially physically permeable area of fine roots, we microscopically evaluated the point of secondary xylem appearance and calculated the geometric area of root portions with primary structure (RAI _micro ). We termed the area of electrically conductive root surface as the active (ion) absorptive area (RAI _mei ) and measured its extent by the modified earth impedance (MEI) method.

Results

The highest values for absorptive root areas at the two experimental sites we obtained with the scanning method (RAI _scan was considered to be 100%), followed by the RAI _micro (51%) and RAI _mei (32%). RAImei reached about 2/3 of RAImicro. The surface area of the ectomycorrhizal hyphae was an order of magnitude larger than that of all fine roots, but the MEI did not measure such increase.

Conclusions

We showed that the absorptive root area, indirectly estimated by the MEI, provides consistent results that approach the values obtained for fine roots with a primary structure estimated by traditional direct methods. The similar range of the values for the absorptive root surface area obtained by microscopy and by the MEI method indicates that this method is feasible and that it could be used to determine the extent of active absorptive root surface areas in forests.     

Life cycle assessment in green chemistry: overview of key parameters and methodological concerns

Purpose

Several articles within the area of green chemistry often promote new techniques or products as ‘green’ or ‘more environmentally benign’ than their conventional counterpart although these articles often do not quantitatively assess the environmental performance. In order to do this, life cycle assessment (LCA) is a valuable methodology. However, on the planning stage, a full-scale LCA is considered to be too time consuming and complicated. Two reasons for this have been recognised, the method is too comprehensive and it is hard to find inventory data. In this review, key parameters are presented with the purpose to reduce the time-consuming steps in LCA.

Methods

In this review, several LCAs of so-called ‘green chemicals’ are analysed and key parameters and methodological concerns are identified. Further, some conclusions on the environmental performance of chemicals were drawn.

Results and discussion

For fossil-based platform chemicals several LCAs exists but for chemicals produced with industrial biotechnology or from renewable resources the number of LCAs is limited, with the exception of biofuels, for which a large number of studies are made. In the review, a significant difference in the environmental performance of bulk and fine chemicals was identified. The environmental performance of bulk chemicals are closely connected to the production of the raw material and thereby different land use aspects. Here, a lot can be learnt from biofuel LCAs. In many of the reviewed articles focusing on bulk chemicals a comparison regarding fossil and renewable raw material was done. In most of the comparisons the renewable alternative turned out to be more environmentally preferable, especially for the impact on GWP and energy use. However, some environmental concerns were identified as important to include to assess overall environmental concern, for example eutrophication and the use of land.

Conclusions

To assess the environmental performance of green chemicals, quantitative methods are needed. For this purpose, both simple metrics and more comprehensive methods have been developed, one recognised method being LCA. However, this method is often too time consuming to be valuable in the process planning stage. This is partly due to a lack of available inventory data, but also because the method itself is too comprehensive. Here, key parameters for the environmental performance and methodological concerns were described to facilitate a faster and simpler use of LCA of green chemicals in the future.     

Towards life cycle sustainability assessment: drawing on the NEEDS project’s total cost and multi-criteria decision analysis ranking methods

Purpose

In the European Union project New Energy Externalities Development for Sustainability (NEEDS), power generation technologies were ranked by means of two sustainability assessment approaches. The total costs approach, adding private and external costs, and a multi-criteria decision analysis (MCDA) were used, integrating social, economic and environmental criteria. Both approaches relied on environmental indicators based on life cycle assessment. This study aims to analyse the extent to which the development of life cycle sustainability assessment (LCSA) can draw on these ranking methods.

Methods

The approaches to rank technologies in the NEEDS project are reviewed in terms of similarities and differences in concept, quantification and scope. Identified issues are discussed and set into perspective for the development of a potential future LCSA framework.

Results and discussion

The NEEDS MCDA and total costs considerably overlap regarding issues covered, except for several social aspects. Beyond total costs being limited to private and external costs, most notable conceptual differences concern the coverage of pecuniary (i.e. price change-induced) external effects, and potential double-counting for instance of resource depletion or specific cost components. External costs take account of the specific utility changes of those affected, requiring a rather high level of spatial and temporal detail. This allows addressing intra- and inter-generational aspects. Differences between both ranking methods and current LCSA methods concern the way weighting is performed, the social aspects covered and the classification of indicators according to the three sustainability dimensions. The methods differ in the way waste, accidents or intended impacts are taken into account. An issue regarding the definition of truly comparable products has also been identified (e.g. power plants).

Conclusions

For the development of LCSA, the study suggests that taking a consequential approach allows assessing pecuniary effects and repercussions of adaptation measures, relevant for a sustainability context, and that developing a life cycle impact assessment for life cycle costing would provide valuable information. The study concludes with raising a few questions and providing some suggestions regarding the development of a consistent framework for LCSA: whether the analyses in LCSA shall be distinguished into the three dimensions of sustainable development at the inventory or the impact level also with the aim to avoid double-counting, whether or not LCSA will address exceptional events, whether or not benefits shall be accounted for and how to deal with methodological and value choices (e.g. through sensitivity analyses).     

Environmental impacts of hybrid,plug-in hybrid,and battery electric vehicles—what can we learn from life cycle assessment?

Purpose

The purpose of this review article is to investigate the usefulness of different types of life cycle assessment (LCA) studies of electrified vehicles to provide robust and relevant stakeholder information. It presents synthesized conclusions based on 79 papers. Another objective is to search for explanations to divergence and “complexity” of results found by other overviewing papers in the research field, and to compile methodological learnings. The hypothesis was that such divergence could be explained by differences in goal and scope definitions of the reviewed LCA studies.

Methods

The review has set special attention to the goal and scope formulation of all included studies. First, completeness and clarity have been assessed in view of the ISO standard’s (ISO 2006a, b) recommendation for goal definition. Secondly, studies have been categorized based on technical and methodological scope, and searched for coherent conclusions.

Results and discussion

Comprehensive goal formulation according to the ISO standard (ISO 2006a, b) is absent in most reviewed studies. Few give any account of the time scope, indicating the temporal validity of results and conclusions. Furthermore, most studies focus on today’s electric vehicle technology, which is under strong development. Consequently, there is a lack of future time perspective, e.g., to advances in material processing, manufacturing of parts, and changes in electricity production. Nevertheless, robust assessment conclusions may still be identified. Most obvious is that electricity production is the main cause of environmental impact for externally chargeable vehicles. If, and only if, the charging electricity has very low emissions of fossil carbon, electric vehicles can reach their full potential in mitigating global warming. Consequently, it is surprising that almost no studies make this stipulation a main conclusion and try to convey it as a clear message to relevant stakeholders. Also, obtaining resources can be observed as a key area for future research. In mining, leakage of toxic substances from mine tailings has been highlighted. Efficient recycling, which is often assumed in LCA studies of electrified vehicles, may reduce demand for virgin resources and production energy. However, its realization remains a future challenge.

Conclusions

LCA studies with clearly stated purposes and time scope are key to stakeholder lessons and guidance. It is also necessary for quality assurance. LCA practitioners studying hybrid and electric vehicles are strongly recommended to provide comprehensive and clear goal and scope formulation in line with the ISO standard (ISO 2006a, b).     

Neuroregeneration in neurodegenerative disorders

Background

Chronic cerebrospinal venous insufficiency (CCSVI) has recently been reported to be associated with multiple sclerosis (MS). However, its actual prevalence, possible association with specific MS phenotypes, and potential pathophysiological role are debated.

Method

We analysed the clinical data of 710 MS patients attending six centres (five Italian and one Canadian). All were submitted to venous Doppler sonography and diagnosed as having or not having CCSVI according to the criteria of Zamboni et al.

Results

Overall, CCSVI was diagnosed in 86% of the patients, but the frequency varied greatly between the centres. Even greater differences were found when considering singly the five diagnostic criteria proposed by Zamboni et al. Despite these differences, significant associations with clinical data were found, the most striking being age at disease onset (about five years greater in CCSVI-positive patients) and clinical severity (mean EDSS score about one point higher in CCSVI-positive patients). Patients with progressive MS were more likely to have CCSVI than those with relapsing-remitting MS.

Conclusion

The methods for diagnosing CCSVI need to be refined, as the between-centre differences, particularly in single criteria, were excessively high. Despite these discrepancies, the strong associations between CCSVI and MS phenotype suggest that the presence of CCSVI may favour a later development of MS in patients with a lower susceptibility to autoimmune diseases and may increase its severity.