Spatial Differentiation in the Characterisation of Photochemical Ozone Formation: The EDIP2003 Methodology

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DOI: http://dx.doi.org/10.1065/lca2006.04.014

Background, Aims and Scope

In the life cycle of a product, emissions take place at many different locations. The location of the source and its surrounding conditions influence the fate of the emitted pollutant and the subsequent exposure it causes. This source of variation is normally neglected in Life Cycle Impact Assessment (LCIA), although it is well known that the impacts predicted by site-generic LCIA in some cases differ significantly from the actual impacts. Environmental impacts of photochemical ozone (ground-level ozone) depend on parameters with a considerable geographical variability (like emission patterns and population densities). A spatially differentiated characterisation model thus seems relevant.

Methods

and Results. The European RAINS model is applied for calculation of site-dependent characterisation factors for Non-Methane Volatile Organic Compounds (NMVOCs) and nitrogen oxides (NOx) for 41 countries or regions within Europe, and compatible characterisation factors for carbon monoxide (CO) are developed based on expert judgement. These factors are presented for three emission years (1990, 1995 and 2010), and they address human health impacts and vegetation impacts in two separate impacts categories, derived from AOT40 and AOT60 values respectively. Compatible site-generic characterisation factors for NMVOC, NOx, CO and methane (CH4) are calculated as emission-weighted European averages to be applied on emissions for which the location is unknown. The site-generic and site-dependent characterisation factors are part of the EDIP2003 LCIA methodology. The factors are applied in a specific case study, and it is demonstrated how the inclusion of spatial differentiation may alter the results of the photochemical ozone characterisation of life cycle impact assessment.

Discussion

and Conclusions. Compared to traditional midpoint characterisation modelling, this novel approach is spatially resolved and comprises a larger part of the cause-effect chain including exposure assessment and exceeding of threshold values. This positions it closer to endpoint modelling and makes the results easier to interpret. In addition, the developed model allows inclusion of the contributions from NOx, which are ne- glected when applying the traditional approaches based on Photochemical Ozone Creation Potentials (POCPs). The variation in site-dependent characterisation factors is far larger than the variation in POCP factors. It thus seems more important to represent the spatially determined variation in exposure than the difference in POCP among the substances.

     

A new approach for a modular valuation of LCAs

Goal Scope and Background

Qualitative valuation methods carefully try to avoid an aggregation across impact categories. However, such an aggregation often helps in obtaining a clear result for the valuation (which product scores better?). This article presents a new valuation method that uses an iterative approach. The application is demonstrated by the help of a case study for electric motors in trains.

Methods / Main Features

The approach combines two existing, unique valuation methods described earlier in literature, which both are of a rather non-aggregating nature, in line with ISO requirements, and were designed to be performed by LCA experts. The method is implemented in a computer software. Besides constants used within the method, the software needs as input solely indicator values from the Impact Assessment.

Results and Discussion

The iterative nature of these methods itself, and especially the combination of these methods, helps in achieving a valuation result for the LCA with not more subjective and aggregating elements than necessary. Subjective elements are clearly separated from others. The algorithm seems highly sensitive to changes in impact categories regarded as important ones. The implementation in software greatly eases the application of the method by transferring routine work from LCA experts to a machine. It ensures a reproducible result and prevents erroneous steps in a rather complicated valuation procedure. It further helps in hiding the complexity of the method from the user.

Conclusion

The approach of combining valuation methods in LCAs seems a fruitful one, and shows benefits when implemented in computer software, in terms of usability, and in terms of a more reproducible application. Care has to be taken to make sure users know what they do when performing an automated valuation procedure.

Outlook

We see three ways for extending the approach, namely: (i) become part of a toolbox of different valuation procedures; (ii) explicitly cope with uncertainty, and (iii) include different values for normalisation, in different regions worldwide. The software will be made available also in a stand alone version.

     

Ecosystem quality in LCIA: status quo,harmonization, and suggestions for the way forward

Purpose

Life cycle impact assessment (LCIA) results are used to assess potential environmental impacts of different products and services. As part of the UNEP-SETAC life cycle initiative flagship project that aims to harmonize indicators of potential environmental impacts, we provide a consensus viewpoint and recommendations for future developments in LCIA related to the ecosystem quality area of protection (AoP). Through our recommendations, we aim to encourage LCIA developments that improve the usefulness and global acceptability of LCIA results.

Methods

We analyze current ecosystem quality metrics and provide recommendations to the LCIA research community for achieving further developments towards comparable and more ecologically relevant metrics addressing ecosystem quality.

Results and discussion

We recommend that LCIA development for ecosystem quality should tend towards species-richness-related metrics, with efforts made towards improved inclusion of ecosystem complexity. Impact indicators—which result from a range of modeling approaches that differ, for example, according to spatial and temporal scale, taxonomic coverage, and whether the indicator produces a relative or absolute measure of loss—should be framed to facilitate their final expression in a single, aggregated metric. This would also improve comparability with other LCIA damage-level indicators. Furthermore, to allow for a broader inclusion of ecosystem quality perspectives, the development of an additional indicator related to ecosystem function is recommended. Having two complementary metrics would give a broader coverage of ecosystem attributes while remaining simple enough to enable an intuitive interpretation of the results.

Conclusions

We call for the LCIA research community to make progress towards enabling harmonization of damage-level indicators within the ecosystem quality AoP and, further, to improve the ecological relevance of impact indicators.

     

LCA of electronic products

Intention, Goal, Scope, Background

A new paradigm called System-In-a-Package (SIP) is expected to represent the wave of future microsystem packaging and integration. No environmental assessment has been made of manufacturing processes for SIP and the purpose of this paper is to assess the upstream environmental impact of the process used by Chalmers to manufacture an electronic product using the SIP technology.

Objectives

This paper aims at an environmental assessment of a gallium arsenide (GaAs) Monolithic Microwave Integrated Circuit (MMIC) Switch Product based on a so-called SIP concept on a Liquid Crystalline Polymer (LCP) substrate. This study focuses on the identification of environmentally substantial upstream processes from cradle-to-gate for this product.

Methods

This work is based on a life cycle inventory model that has been developed earlier by the authors, and this model is now applied to the system including the straight-line manufacturing processes in the facilities of the Microtechnology Centre (MC2) at Chalmers University of Technology and the manufacturing processes of raw materials in the upstream processes. A main scenario was built in the LCA software EcoLab corresponding to the linear process in MC2 and other manufacturing processes were identified in the upstream which were used to develop the upstream process tree.

Results and Discussion

The spin coating of photoresistant material has the highest environmental impact within the system boundaries and the uncertainty of the results is estimated to be small. The exposure and development as well as deposition stages also give impacts, both for the copper and resistant material deposition. In the manufacturing processes inside MC2, the electricity consumption clearly dominates. The results predominantly reflect energy use, whereas toxicological aspects could not be reliably assessed due to lack of data and reliable methods, and therefore needs separate attention. Nevertheless, a toxicology assessment has been made with the Toxic Potential Indicator (TPI), which, compared to a telephone, showed a relatively large value for the switch. The toxic potential of the switch is higher per mass unit than a digital telephone.

Conclusions

The previously developed LCA data collection model worked well for the SIP product. The electricity consumption for the deposition machine and the solvent consumption in spin coating are the two most important hot spots. For greenhouse warming potential the acetone consumption in the spin coating steps is the most significant contributor, and the copper consumption in the copper deposition step dominates for abiotic resource depletion.

Recommendations and Outlook

It is recommended that the machines in the MC2 process lab used to manufacture the SIP product are studied for a longer period of time as it would make the electricity consumption figures more accurate. More electronic packaging concepts, such as System-on-a-chip (SOC) and multichip modules (MCM), should be evaluated and compared to SIP.

     

Developing characterisation factors for land fragmentation impacts on biodiversity in LCA: key learnings from a sugarcane case study

Purpose

Habitat change was identified by the Millennium Ecosystem Assessment as the main direct driver of biodiversity loss. However, while habitat loss is already implemented in Life Cycle Impact Assessment (LCIA) methods, the additional impact on biodiversity due to habitat fragmentation is not assessed yet. Thus, the goal of this study was to include fragmentation effects from land occupation and transformation at both midpoint and endpoint levels in LCIA.

Methods

One promising metric, combining the landscape spatial configuration with species characteristics, is the metapopulation capacity λ, which can be used to rank landscapes in terms of their capacity to support viable populations spatially structured. A methodology to derive worldwide regionalised fragmentation indexes based on λ was used and combined with the Species Fragmented-Area Relationship (SFAR), which relies on λ to assess a species loss due to fragmentation. We adapted both developments to assess fragmentation impacts due to land occupation and transformation at both midpoint and endpoint levels in LCIA. An application to sugarcane production occurring in different geographical areas, more or less sensitive to land fragmentation, was performed.

Results and discussion

The comparison to other existing LCIA indicators highlighted its great potential for complementing current assessments through fragmentation effect inclusion. Last, both models were discussed through the evaluation grid used by the UNEP-SETAC land use LCIA working group for biodiversity impact assessment models.

Conclusions

Midpoint and endpoint characterisation factors were successfully developed to include the impacts of habitat fragmentation on species in LCIA. For now, they are provided for bird species in all forest ecoregions belonging to the biodiversity hotspots. Further work is required to develop characterisation factors for all taxa and all terrestrial ecoregions.

     

Impacts of onshore wind energy production on birds and bats: recommendations for future life cycle impact assessment developments

Purpose

Models for quantifying impacts on biodiversity from renewable energy technologies are lacking within life cycle impact assessment (LCIA). We aim to provide an overview of the effects of wind energy on birds and bats, with a focus on quantitative methods. Furthermore, we investigate and provide the necessary background for how these can be integrated into new developments of LCIA models in future.

Methods

We reviewed available literature summarizing the effects of wind energy developments on birds and bats. We provide an overview of available quantitative assessment methods that have been employed outside of the LCIA framework to model the different impacts of wind energy developments on wildlife. Combining the acquired knowledge on impact pathways and associated quantitative methods, we propose possibilities for future approaches for a wind energy impact assessment methodology for LCIA.

Results and discussion

Wind energy production has impacts on terrestrial biodiversity through three main pathways: collision, disturbance, and habitat alterations. Birds and bats are consistently considered the most affected taxonomic groups, with different responses to the before-mentioned impact pathways. Outside of the LCIA framework, current quantitative impact assessment prediction models include collision risk models, species distribution models, individual-based models, and population modeling approaches. Developed indices allow scaling of species-specific vulnerability to mortality, disturbance, and/or habitat alterations.

Conclusions

Although insight into the causes behind collision risk, disturbance, and habitat alterations for bats and birds is still limited, the current knowledge base enables the development of a robust assessment tool. Modeling the impacts of habitat alterations, disturbance, and collisions within an LCIA framework is most appropriate using species distribution models as those enable the estimation of species’ occurrences across a region. Although local-scale developments may be more readily feasible, further up-scaling to global coverage is recommended to allow comparison across regions and technologies, and to assess cumulative impacts.

     

Cradle-to-gate life cycle assessment of global manganese alloy production

Purpose

Manganese is a metal used extensively in everyday life, particularly in structural steel. Despite the importance of manganese as an essential alloying element in steel and stainless steel, the environmental profile of manganese alloys lacked globally representative, primary industry data. The International Manganese Institute (IMnI) and Hatch completed the first global life cycle assessment (LCA) of manganese alloy production, providing environmental benchmarks and a firm foundation of accurate data with which to inform other industry-led initiatives.

Methods

The study compiled primary data from 16 ore and alloy producers worldwide, covering 18 % of global ore production and 8 % of global alloy production for 2010. This peer-reviewed, ISO 14040 compliant LCA covers the cradle-to-gate life cycles of silicomanganese, ferromanganese, and refined ferromanganese. The study provides a comprehensive picture of global environmental performance, quantifying energy consumption, global warming potential (GWP), acidification potential (AP), photochemical ozone creation potential (POCP), primary water use, and primary waste generation. A novel model architecture was devised to generate process, site, and cradle-to-gate LCAs for single and multiple sites simultaneously, extracting greater value from the LCA process by facilitating environmental and operational benchmarking within the industry.

Results and discussion

The results of the study show that total GWP, AP, and POCP for 1 kg of average manganese alloy was 6.0 kg CO₂e, 45 g SO₂e, and 3 g C₂H₄e, respectively. Electricity demand and coal and coke consumption during smelting are the dominant operating parameters contributing to environmental performance. On-site air emission measures (GWP, POCP, NO_X, and particulate matter (PM)) contributed 25 to 35 % of total life cycle emissions. Overburden and waste rock were the most significant primary solid waste flows by mass. The study provides a resource for improvement at the global industry and site scales by establishing benchmarks, identifying hotspots, and quantifying the benefits of efficiency savings through process optimization.

Conclusions

This LCA provides accurate primary data to improve steel and stainless steel product LCAs and communicate the environmental performance of the industry in quantitative terms. It facilitates dialogue between manganese producers and consumers through a shared understanding of the environmental profile of the industry. Through leveraging the study to identify hotspots within the manganese supply chain, producers can work both independently and collectively towards improving the environmental and economic performance of manganese alloys.

     

Addressing water needs of freshwater ecosystems in life cycle impact assessment of water consumption: state of the art and applicability of ecohydrological approaches to ecosystem quality characterization

Purpose

In recent history, human development overbalanced towards economic growth has often been accompanied by the degradation and reduction of freshwater resources at the expense of freshwater dependent ecosystems. For their subsistence and correct functioning, understanding environmental water requirements (EWR) represents an area of great interest for life cycle impact assessment (LCIA) and it has been only marginally explored. The aim of this paper is to investigate how this concept has evolved in ecological and hydrological literature and how it can be better integrated in LCIA, to identify potential options for improvement of LCIA indicators in the short, mid and long term.

Methods

To address the limitations of existing LCIA approaches in modelling EWR, four families of EWR methods have been reviewed, namely hydrological, hydraulic, habitat simulation and holistic methods. Based on existing scientific literature and their broad application, 24 methods have been selected and their suitability to be adopted in LCIA has been evaluated against nine criteria, with regard to data management issues, accuracy, scientific robustness, and potential for future development. A semi-quantitative performance score has been subsequently assigned for each criterion, showing the main strengths and weaknesses of selected methods.

Results and discussion

The underlying rationale of the chosen approaches is markedly different, likewise the input information needed and results applicability. Hydrological methods are well suited for the development of global models and they are the only ones currently considered in LCIA, although their applicability remains limited to water stress indicators. Habitat modelling is identified as an essential step for the development of mechanistic LCIA models and endpoint indicators. In this respect, hydraulic, habitat simulation and holistic methods are fit for the purpose. However, habitat simulation methods represent the best compromise between scientific robustness and applicability in LCIA. For this reason, a conceptual framework for the development of habitat-based characterization factors has been proposed. Among the evaluated habitat simulation methods, ESTIMHAB showed the best performance and was the method retained for the development of an LCIA model that will assess the consequences of water consumption on stream ecosystems.

Conclusions

This study identifies the advantages of specific modelling approaches for the assessment of water requirements for ecosystems. Selected methods could support the development of LCIA models at different levels. In the short-term for improving environmental relevance of water stress indicators, and in the mid/long-term to build up midpoint habitat indicators relating water needs of ecosystems with new endpoint metrics.

     

Optimization of fecal sample preparation for untargeted LC-HRMS based metabolomics

Introduction

Collecting feces is easy. It offers direct outcome to endogenous and microbial metabolites.

Objectives

In a context of lack of consensus about fecal sample preparation, especially in animal species, we developed a robust protocol allowing untargeted LC-HRMS fingerprinting.

Methods

The conditions of extraction (quantity, preparation, solvents, dilutions) were investigated in bovine feces.

Results

A rapid and simple protocol involving feces extraction with methanol (1/3, M/V) followed by centrifugation and a step filtration (10 kDa) was developed.

Conclusion

The workflow generated repeatable and informative fingerprints for robust metabolome characterization.

     

Uncertainty in LCA case study due to allocation approaches and life cycle impact assessment methods

Purpose

Uncertainty is present in many forms in life cycle assessment (LCA). However, little attention has been paid to analyze the variability that methodological choices have on LCA outcomes. To address this variability, common practice is to conduct a sensitivity analysis, which is sometimes treated only at a qualitative level. Hence, the purpose of this paper was to evaluate the uncertainty and the sensitivity in the LCA of swine production due to two methodological choices: the allocation approach and the life cycle impact assessment (LCIA) method.

Methods

We used a comparative case study of swine production to address uncertainty due to methodological choices. First, scenario variation through a sensitivity analysis of the approaches used to address the multi-functionality problem was conducted for the main processes of the system product, followed by an impact assessment using five LCIA methods at the midpoint level. The results from the sensitivity analysis were used to generate 10,000 independent simulations using the Monte Carlo method and then compared using comparison indicators in histogram graphics.

Results and discussion

Regardless of the differences between the absolute values of the LCA obtained due to the allocation approach and LCIA methods used, the overall ranking of scenarios did not change. The use of the substitution method to address the multi-functional processes in swine production showed the highest values for almost all of the impact categories, except for freshwater ecotoxicity; therefore, this method introduced the greater variations into our analysis. Regarding the variation of the LCIA method, for acidification, eutrophication, and freshwater ecotoxicity, the results were very sensitive. The uncertainty analysis with the Monte Carlo simulations showed a wide range of results and an almost equal probability of all the scenarios be the preferable option to decrease the impacts on acidification, eutrophication, and freshwater ecotoxicity. Considering the aggregate result variation across allocation approaches and LCIA methods, the uncertainty is too high to identify a statistically significant alternative.

Conclusions

The uncertainty analysis showed that performing only a sensitivity analysis could mislead the decision-maker with respect to LCA results; our analysis with the Monte Carlo simulation indicates no significant difference between the alternatives compared. Although the uncertainty in the LCA outcomes could not be decreased due to the wide range of possible results, to some extent, the uncertainty analysis can lead to a less uncertain decision-making by demonstrating the uncertainties between the compared alternatives.

     

Life cycle assessment of Chinese radial passenger vehicle tire

Purpose

We evaluated and quantified the environmental impact of a radial tire product for passenger vehicles throughout the product’s life cycle to identify key stages that contribute to the overall environmental burden and to find ways to reduce these burdens effectively. The study covers all relevant life cycle stages, from the acquisition of raw materials to the production, use, and end of life.

Methods

Data collected onsite in 2014 by one of the largest Chinese tire companies were used in the assessment. The evaluation is presented in terms of individual impact category according to the CML model. Five impact categories (i.e., global warming potential (GWP), acidification potential (AP), photochemical oxidant creation potential (POCP), eutrophication potential (EP), and human toxicity potential (HTP)) were considered. The research was conducted in accordance with the ISO 14040/14044 standards.

Results and discussion

Fuel (gasoline) consumption represents an important contribution to most impact categories, including the GWP, AP, POCP, and EP, during the use stage. The largest contributor to the HTP category is raw material acquisition, mainly because of the impact of the production of organic chemicals. In the end-of-life stage, assuming that 100 % of used tires are collected and recycled to produce reclaimed rubber, the GWP, EP, and HTP contributions are negative, whereas those to the AP and POCP are positive. During the raw material acquisition stage, natural rubber, synthetic rubber, carbon black, and organic chemicals represent the largest contribution to the environmental impact categories. During the production stage, the compound blending process is the largest contributor to the AP and POCP, whereas vulcanizing and testing contribute most to the GWP, EP, and HTP.

Conclusions

Vehicle fuel consumption and its proportion consumed by the tires during the use stage are key factors that contribute to environmental impact during tire life. Further investigations should be conducted to decrease the impact of these factors and improve the environmental performance of tire products.

     

Towards harmonizing natural resources as an area of protection in life cycle impact assessment

Purpose

In this paper, we summarize the discussion and present the findings of an expert group effort under the umbrella of the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative proposing natural resources as an Area of Protection (AoP) in Life Cycle Impact Assessment (LCIA).

Methods

As a first step, natural resources have been defined for the LCA context with reference to the overall UNEP/SETAC Life Cycle Impact Assessment (LCIA) framework. Second, existing LCIA methods have been reviewed and discussed. The reviewed methods have been evaluated according to the considered type of natural resources and their underlying principles followed (use-to-availability ratios, backup technology approaches, or thermodynamic accounting methods).

Results and discussion

There is currently no single LCIA method available that addresses impacts for all natural resource categories, nor do existing methods and models addressing different natural resource categories do so in a consistent way across categories. Exceptions are exergy and solar energy-related methods, which cover the widest range of resource categories. However, these methods do not link exergy consumption to changes in availability or provisioning capacity of a specific natural resource (e.g., mineral, water, land etc.). So far, there is no agreement in the scientific community on the most relevant type of future resource indicators (depletion, increased energy use or cost due to resource extraction, etc.). To address this challenge, a framework based on the concept of stock/fund/flow resources is proposed to identify, across natural resource categories, whether depletion/dissipation (of stocks and funds) or competition (for flows) is the main relevant aspect.

Conclusions

An LCIA method—or a set of methods—that consistently address all natural resource categories is needed in order to avoid burden shifting from the impact associated with one resource to the impact associated with another resource. This paper is an important basis for a step forward in the direction of consistently integrating the various natural resources as an Area of Protection into LCA.

     

Impacts from hydropower production on biodiversity in an LCA framework—review and recommendations

Purpose

Expanding renewable energy production is widely accepted as a promising strategy in climate change mitigation. However, even renewable energy production has some environmental impacts, some of which are not (yet) covered in life cycle impact assessment (LCIA). We aim to identify the most important cause-effect pathways related to hydropower production on biodiversity, as one of the most common renewable energy sources, and to provide recommendations for future characterization factor (CF) development.

Methods

We start with a comprehensive review of cause-effect chains related to hydropower production for both aquatic and terrestrial biodiversity. Next, we explore contemporary coverage of impacts on biodiversity from hydropower production in LCA. Further, we select cause-effect pathways displaying some degree of consistency with existing LCA frameworks for method development recommendations. For this, we compare and contrast different hydrologic models and discuss how existing LCIA methodologies might be modified or combined to improve the assessment of biodiversity impacts from hydropower production.

Results and discussion

Hydropower impacts were categorized into three overarching impact pathways: (1) freshwater habitat alteration, (2) water quality degradation, and (3) land use change. Impacts included within these pathways are flow alteration, geomorphological alteration to habitats, changes in water quality, habitat fragmentation, and land use transformation. For the majority of these impacts, no operational methodology exists currently. Furthermore, the seasonal nature of river dynamics requires a level of temporal resolution currently beyond LCIA modeling capabilities. State-of-the-art LCIA methods covering biodiversity impacts exist for land use and impacts from consumptive water use that can potentially be adapted to cases involving hydropower production, while other impact pathways need novel development.

Conclusions

In the short term, coverage of biodiversity impacts from hydropower could be significantly improved by adding a time step representing seasonal ecological water demands to existing LCIA methods. In the long term, LCIA should focus on ecological response curves based on multiple hydrologic indices to capture the spatiotemporal aspects of river flow, by using models based on the “ecological limits to hydrologic alteration” (ELOHA) approach. This approach is based on hydrologic alteration-ecological response curves, including site-specific environmental impact data. Though data-intensive, ELOHA represents the potential to build a global impact assessment framework covering multiple ecological indicators from local impacts. Further, we recommend LCIA methods based on degree of regulation for geomorphologic alteration and a fragmentation index based on dam density for “freshwater habitat alteration,” which our review identified as significant unquantified threats to aquatic biodiversity.

     

Intensive determination of storage condition effects on human plasma metabolomics

Introduction

Human plasma metabolomics offer powerful tools for understanding disease mechanisms and identifying clinical biomarkers for diagnosis, efficacy prediction and patient stratification. Although storage conditions can affect the reliability of data from metabolites, strict control of these conditions remains challenging, particularly when clinical samples are included from multiple centers. Therefore, it is necessary to consider stability profiles of each analyte.

Objectives

The purpose of this study was to extract unstable metabolites from vast metabolome data and identify factors that cause instability.

Method

Plasma samples were obtained from five healthy volunteers, were stored under ten different conditions of time and temperature and were quantified using leading-edge metabolomics. Instability was evaluated by comparing quantitation values under each storage condition with those obtained after ?80 °C storage.

Result

Stability profiling of the 992 metabolites showed time- and temperature-dependent increases in numbers of significantly changed metabolites. This large volume of data enabled comparisons of unstable metabolites with their related molecules and allowed identification of causative factors, including compound-specific enzymatic activity in plasma and chemical reactivity. Furthermore, these analyses indicated extreme instability of 1-docosahexaenoylglycerol, 1-arachidonoylglycerophosphate, cystine, cysteine and N⁶-methyladenosine.

Conclusion

A large volume of data regarding storage stability was obtained. These data are a contribution to the discovery of biomarker candidates without misselection based on unreliable values and to the establishment of suitable handling procedures for targeted biomarker quantification.

     

Quantitative analysis of tetrahydrofolate metabolites from <Emphasis Type="Italic">clostridium autoethanogenum</Emphasis>

Introduction

Quantification of tetrahydrofolates (THFs), important metabolites in the Wood–Ljungdahl pathway (WLP) of acetogens, is challenging given their sensitivity to oxygen.

Objective

To develop a simple anaerobic protocol to enable reliable THFs quantification from bioreactors.

Methods

Anaerobic cultures were mixed with anaerobic acetonitrile for extraction. Targeted LC–MS/MS was used for quantification.

Results

Tetrahydrofolates can only be quantified if sampled anaerobically. THF levels showed a strong correlation to acetyl-CoA, the end product of the WLP.

Conclusion

Our method is useful for relative quantification of THFs across different growth conditions. Absolute quantification of THFs requires the use of labelled standards.

     

Freshwater ecotoxicity characterization factors for aluminum

Purpose

Aluminum (Al) is an abundant, non-essential element with complex geochemistry and aquatic toxicity. Considering its complex environmental behavior is critical for providing a reasonable estimate of its potential freshwater aquatic ecotoxicity in the context of Life Cycle Impact Assessment (LCIA).

Methods

Al characterization factors (CFs) are calculated using the following: (1) USEtox^? model version 2.1 for environmental fate, (2) MINEQL+ to estimate the distribution of Al between the solid phase precipitate and total dissolved Al, (3) WHAM 7 for Al speciation within the total dissolved phase, and (4) Biotic Ligand Model (BLM) and Free Ion Activity Model (FIAM) for ecotoxicity estimation for seven freshwater archetypes and default landscape properties for the European continent. The sensitivity of the CFs to aquatic chemistry parameters is calculated. New CFs are compared with Dong et al. (Chemosphere 112:26–33, 2014) and default CF calculated by USEtox 2.1.

Results and discussion

Al CFs vary over 5 orders of magnitude between the seven archetypes, with an arithmetic average CF_ave of 0.04 eq 1,4-DCB (recommended for use), geometric mean CF_geo of 0.0014 eq 1,4-DCB, and weighted average CF_wt of 0.026 eq 1,4-DCB. These values are lower (less toxic) than those for Cu, Ni, Zn, and Pb (with one exception). The effect factor (EF) contributed most to this variability followed by the bioavailability factor (BF), varying over 8 and 4 orders of magnitude, respectively. These revised CFs are 2–6 orders of magnitude lower than those presented by Dong et al. (Chemosphere 112:26–33, 2014) mainly because of consideration of Al precipitation.

Conclusions

Freshwater archetype-specific Al CFs for freshwater ecotoxicity that address the effect of Al speciation on bioavailability (BF) and ecotoxicity (EF) have been calculated, and a CF of 0.04 eq 1,4-DCB is recommended for use in generic LCA. For site-specific LCA, the choice of water chemistry and, in particular, pH, and consideration of metal precipitation could significantly influence results.

Practical implications

Incorporating estimates of metal speciation and its effect on aquatic toxicity is essential when conducting LCIA. Along with metal speciation estimates, the values derived from the definition of water chemistry parameters must also be included into LCIA. For site-generic assessments, we recommend using the arithmetic average of metal CFs. We also recommend using FIAM as a suitable alternative to BLM to estimate EF if the latter is not available. Consideration of metal speciation is essential for providing more realistic estimates of Al freshwater ecotoxicity in the context of LCIA.

     

Characterization of trotter horses urine metabolome by means of proton nuclear magnetic resonance spectroscopy

Background

Metabolomics has been recognized as a powerful approach for disease screening. In order to highlight potential health issues in subjects, a key factor is the possibility to compare quantitatively the metabolome of their biofluids with reference values from healthy individuals. Such efforts towards the systematic characterization of the metabolome of biofluids in perfect health conditions, far from concluded for humans, have barely begun on horses.

Objectives

The present work attempts, for the first time, to give reference quantitative values for the molecules mostly represented in the urine metabolome of horses at rest and under light training, as observable by ¹H-NMR.

Methods

The metabolome of ten trotter horses, four male and six female, ranging from 3 to 8 years of age, has been observed by ¹H-NMR spectroscopy before and after three training sessions.

Results

We could characterize and quantify 54 molecules in trotter horse urine, originated from diet, protein digestion, energy generation or gut-microbial co-metabolism.

Conclusion

We were able to describe how gender, age and exercise affected their concentration, by means of a two steps protocol based on univariate and robust principal component analysis.

     

Notions on the Design and Use of an Ideal Regional or Global LCA Database

Goal, Scope and Background

More and more national and regional life cycle assessment (LCA) databases are being established satisfying the increasing demand on LCA in policy making (e.g. Integrated Product Policy, IPP) and in industry. In order to create harmonised datasets in such unified databases, a common understanding and common rules are required. This paper describes major requirements on the way towards an ideal national background LCA database in terms of co-operation, but also in terms of life cycle inventory analysis (LCI) and impact assessment (LCIA) methodology.

Methods

A classification of disputed methodological issues is made according to their consensus potential. In LCI, three main areas of dissent are identified where consensus seems hardly possible, namely system modelling (consequential versus attributional), allocation (including recycling) and reporting (transparency and progressiveness). In LCIA the time aspect is added to the well-known value judgements of the weighting step.

Results and Discussions

It is concluded that LCA methodology should rather allow for plurality than to urge harmonisation in any case. A series of questions is proposed to identify the most appropriate content of the LCA background database or the most appropriate LCI dataset. The questions help to identify the best suited approach in modelling the product system in general and multioutput and recycling processes in particular. They additionally help to clarify the position with regard to time preferences in LCIA. Intentionally, the answers to these questions are not attributed to particular goal and scope definitions, although some recommendations and clarifying explanations are provided.

Recommendations and Perspective

It is concluded that there is not one single ideal background database content. Value judgements are also present in LCI modelling and require pluralistic solutions; solutions possibly based on the same primary data. It is recommended to focus the methodological discussion on aspects where consensus is within reach, sensible and of added value for all parties.

     

High salt and fat intake,inflammation, and risk of cancer

Background

Inflammatory conditions are involved in the pathophysiology of cancer. Recent findings have revealed that excessive salt and fat intake is involved in the development of severe inflammatory reactions.

Methods

literature search was performed on various online databases (PubMed, Scopus, and Google Scholar) regarding the roles of high salt and fat intake in the induction of inflammatory reactions and their roles in the etiopathogenesis of cancer.

Results

The results indicate that high salt and fat intake can induce severe inflammatory conditions. However, various inflammatory conditions have been strongly linked to the development of cancer. Hence, high salt and fat intake might be involved in the pathogenesis of cancer progression via putative mechanisms related to inflammatory reactions.

Conclusion

Reducing salt and fat intake may decrease the risk of cancer.