Ecological modernization,techno-politics and social life cycle assessment: a view from human geography

Purpose

Although Social Life Cycle Assessment (SLCA) is a growing field of inquiry and intervention, to date, there has been a dearth of engagement between this field and critical social scientists interested in questions of the societal impacts of goods and services. In response, this paper is written from the perspectives of two human geographers, new to the field of SLCA. Our aim is to offer an ‘outsiders’ perspective of, and commentary on, the growing field of SLCA, which we frame as a form of political intervention that seeks to have real-world impacts on the lives and futures of diverse peoples and places.

Methods

To address these questions, we explore SLCA’s underpinning assumptions by critically reviewing the worldviews that inform its methods, including debates in the literature about sustainable development and corporate social responsibility.

Results and discussion

SLCA’s normative and practical applications resonate strongly with an ecological modernization framework. This framework forwards social change via incremental and institutional interventions that promotes continued development, and privileges objectivity, impartiality and the search for a totalizing knowledge of the impacts of good and services.

Conclusions

Exploring SLCA’s epistemological foundations illuminates, and in turn, can help to address some of the key challenges SLCA currently faces. Drawing attention to SLCA’s inheren raison d’etre encourages more debate about the overall intentions and limits of the field, and represents not a weakness but rather its inherent quality of exploring the complex world of social impacts.

     

Customized scoring and weighting approaches for quantifying and aggregating results in social life cycle impact assessment

Purpose

In social life cycle assessment (SLCA), to measure the social performance, it is necessary to consider the subcategory indicators related to each stakeholder dimension, such as workers, local community, society, consumers and value chain participants. Current methods in SLCA scientific literature consider a standard arbitrary linear score set to translate qualitative performances into a quantitative assessment for all subcategory indicators, i.e., it translate a A, B, C, D scoring into a 4, 3, 2, 1 ordinal scale. This assumption does not cover the complexity of the subcategory indicators in the social life cycle assessment phase. The aim of this paper is to set out a customized scoring and weighting approach for impact assessment in SLCA beyond the assumption of arbitrary linearity and equal weighting.

Methods

This method overcomes the linearity assumption and develops specific value functions for each subcategory indicator and an approach to establish the weighting factors between the indicators for each social dimension (workers, local community, and society). The value function and weighting factors are based on the considered opinions of SLCA experts in Québec.

Results and discussion

The results show that value functions with different shapes used to score the performance of the product within each subcategory indicator influence SLCA results and have the potential to reverse the conclusions. The customized score is more realistic than the linear score because it can better capture the complexity of the subcategory indicators based on SLCA expert judgment.

Conclusions

Our approach addresses a methodological weakness of the impact assessment phase of SLCA through a more representative performance of the potential social impacts based on the judgment of the SLCA expert rather than a simplified assumption of linearity and equal weighting among indicators. This approach may be applied to all types of product systems.

Recommendations

The value functions and weighting factors cannot be generalized for all cases and the proposed approach must be adapted for each study. We stopped at the aggregation of the subcategory indicators based on expert judgment at the stakeholder level. If a complete aggregation in a single score is required, we recommend developing a framework that accounts for the value judgment of the decision-maker rather than the SLCA expert.

     

Addressing positive impacts in social LCA—discussing current and new approaches exemplified by the case of vehicle fuels

Purpose

This paper seeks ways to address positive social impacts in social life cycle assessment (SLCA) and attempts to answer two questions: How can the SLCA methodology be improved in order to systematically identify all potential positive impacts in the supply chain? How can positive impacts be taken into consideration along with negative impacts in SLCA? In order for SLCA to be an attractive tool, it needs to provide users with the possibility to include positive impacts, not as variables stipulating lack of negative impacts but rather as fulfilment of positive potentials.

Methods

By scrutinising the social impacts addressed in the SLCA UNEP/SETAC Guidelines today and reviewing approaches for positive impacts in other research fields, a developed approach to capture and aggregate positive social impacts in SLCA is proposed. To exemplify the application, the case of vehicle fuels is used to investigate the possibilities of addressing positive impacts in SLCA. This includes a literature review on potential positive social impacts linked to vehicle fuels.

Results and discussion

The subcategories in the SLCA Guidelines are proposed to be divided into positive and negative impacts and complemented with some additional positive impacts. Related indicators are proposed. A draft approach for assessing positive impacts is developed where the proposed indicators are categorised in four different levels, from low to very high potential positive impact. The possibility to aggregate positive social impacts is discussed. Besides multi-criteria decision analysis (MCDA), few useful ideas for aggregating positive impacts in SLCA were found in the literature that mostly focused on surveys and monetarisation. Positive social impacts linked to vehicle fuels (fossil fuels and biofuels) are identified, and the proposed approach is schematically applied to vehicle fuels.

Conclusions

The SLCA methodology may be refined in order to better identify and assess positive impacts, and approaches developed for capturing and aggregating such impacts are proposed. Challenges of aggregating positive and negative social impacts still remain. The knowledge on social impacts from vehicle fuels could be improved by applying the proposed approach. However, the approach needs more development to be practically applicable.

     

Systematic literature review in social life cycle assessment

Purpose

The main purpose of this review is to investigate the methodology of social life cycle assessment (SLCA) through its application to case studies. In addition, the following research aims to define the trends related to the SLCA by researchers and consultants. This study will help to map the current situation and to highlight the hot spots and weaknesses of the application of the SLCA theory.

Methods

The SLCA could be considered as a useful methodology to provide decision support in order to compare products and/or improve the social effects of the life cycle of a product. Furthermore, the results of the case studies analyzed may influence decision makers significantly. For this reason, a systematic literature review of case studies was carried out in which SLCA was applied in order to analyze closely the application of the stages of this methodology. In this study, the major phases of the technical framework for a SLCA were analyzed. Specific attention was paid to detect the positive impacts that emerged in the case studies, which were also studied by administering a questionnaire to the authors of the analyzed case studies and to a number of experts in the field of SLCA.

Results and discussion

The 35 case studies examined in this paper, even though they do not deviate from the 40 identified by the previous processing, are still significantly different in terms of outcome produced. It is important to clarify that the authors who developed the case studies considered the steps defined in the SETAC/SETAC guidelines, borrowed from the ISO 14044 standard.

Conclusions

The data resulting from this analysis could help both practitioners and researchers to understand what the issues are, on which it is still necessary to investigate and work, in order to solidify the SLCA methodology and define its role in the context of life cycle sustainability assessment (LCSA).

     

The main challenges for social life cycle assessment (SLCA) to support the social impacts analysis of product-service systems

Purpose

This paper aims to investigate the applicability of social life cycle assessment (SLCA) to the social impacts analysis of product-service systems (PSS). The purpose is to discuss the main challenges for this approach to comparing PSS business model alternatives and analyzing the social consequences of PSS introduction into the market.

Methods

Two PSS solutions were considered to investigate the applicability and the challenges for SLCA when applied to PSS assessment. A comparative analysis was discussed based on UNEP/SETAC guidelines. The subcategories and social indicators suggested in the guidelines were analyzed, and the indicators considered suitable for the comparison of PSS alternatives, considering the use phase, were identified. Other indicators from the PSS literature were also added to those from the guidelines. To analyze the consequences of PSS implementation, the applicability of consequential SLCA was discussed.

Results and discussion

The main results pointed out that only a few indicators in the SLCA guidelines could be used for comparative PSS analysis. This occurred because only some of the guidelines could be linked to the processes of each PSS. Other indicators identified in the PSS literature are suggested to complement the comparative analysis of PSS alternatives. Concerning the effects of PSS introduction, it can cause social impacts with regard to the company and stakeholders directly involved in the changes in addition to the effects that may occur in other products and services systems as a result of consumers’ behavior and PSS interaction in the market. The consequential modeling is suggested as appropriate for this analysis.

Conclusions

The SLCA approach can be considered suitable for PSS social issues analysis, although there are limitations for a full analysis in this study. Some major challenges for its applicability were identified. First, PSS functional unit modeling should be investigated considering all PSS elements (products and services) and the functions provided by the system. Second, only few indicators in the guidelines were considered appropriate for PSS comparative analysis before its introduction. Finally, concerning consequential SLCA, this could be explored in the context of PSS, but there is still scarce research on this subject. In short, to establish SLCA as a useful and applicable methodology to assess the social impacts of a PSS, further research is required, especially regarding the consequential SLCA.

     

A historical perspective on the engineering ideologies of sustainability: the case of SLCA

Purpose

The 1990s produced two distinct engineering ideologies of sustainability—one emphasizing engineering innovation and the other emphasizing socio-cultural change. The technological change ideology of sustainability refers to engineering reform controlled and directed by engineers themselves—in other words, technological practices can be improved through the application of expertise. The technopolitics’ ideology of sustainability is about engineering challenge; it places more emphasis on the devolution of expertise from the existing model of engineering and society, and it questions the dominant values of engineering practice. In this article, I present a historico-philosophical perspective on the development of social life cycle assessment (SLCA) to highlight how the dialectic between sustainability and engineering has been defined largely by the ideology of technological change.

Methods

I provide original historical evidence regarding the roles of key actors and institutions in fitting the life cycle perspective and corporate social responsibility (CSR) into sustainable development. Primary data for this chapter is based on archival materials as well as on 30, in depth, semi-structured interviews with North American and European LCA and SLCA experts. Other primary data were collected from participant observation in SLCA webinars and workshops.

Results and discussion

Technology is at the heart of SLCA—it is a shared faith in technology as the solution. At the same time, there is growing appreciation amongst SLCA proponents that such technology must be construed more critically. Although it remains a subaltern current within LCA, SLCA is evidence of how technological change and technopolitics are starting to converge and influence each other—a probe toward a more reflective form of engineering discourse and toward the formation of a new hybrid sustainability ideology.

Conclusions

SLCA, I argue in this article, is an ideological hybrid where there are many spots of dissent and disagreement but also some surprising fundamental alignments between those who see engineering as techniques and those who believe that engineering needs to be socially and politically contextualized. Yet, even as the concepts of sustainable development, CSR, and LCA provide the intellectual and institutional mold within which SLCA becomes conceivable, these concepts may also obscure the historicity of sustainability engineering.

     

A literature review of type I SLCA—making the logic underlying methodological choices explicit

Purpose

The Social Life Cycle Assessment guidelines (UNEP-SETAC 2009) distinguish two different SLCA approaches, type I and type II. Few comprehensive and analytical reviews have been undertaken to examine the multiplicity of approaches that have been developed within type I SLCA. This paper takes on the task of exploring the evaluation methods used in type I SLCA methods.

Methods

In order to tackle this work, a critical literature review was undertaken, covering a total of 32 reviewed articles, ranging from 2006 to 2015. Those articles have been selected for they make explicit reference to type I, performance reference points (PRPs), corporate behavior assessment, and social performance assessment or if their assessment methods generated a result located at the same point as the inventory data, with regards to the impact pathway. The selected articles were analyzed with a focus on the inventory data used, the aggregation of inventory data on the functional unit, and the type of characterization and weighting methods used. This analysis allowed to make explicit the often implicit logic underlying the evaluation methods and to identify the common denominators of type I SLCA.

Results and discussion

The analysis highlighted the multiplicity of approaches that are comprised within type I SLCA today, both in terms of the data collected (in particular, its positioning along the impact pathway); the presence of some optional steps, such as the scaling of inventory data on the functional unit (FU); and in terms of the different characterization and weighting steps. With regards to data collection, this review has highlighted that the furthest indicators are positioned along the impact pathway, the hardest it is to justify the link between them and the activities of companies in the product system. The analysis also suggested that an important differentiating factor among type I SLCA methods lies in “what the inventory data is assessed against” at the characterization step and how it is ultimately weighted. To illustrate this, a typology of six characterization methods and five types of weighting methods was presented.

Conclusions

It is interesting to identify which approaches are most appropriate to respond to the various questions that SLCA aims to respond to. A question that arises is what approaches are most likely to tell us anything about the impact of a product system on social well-being? This question is particularly relevant in the absence of well-documented impact pathways between activities within product systems and impact on social well-being.

     

Social life cycle assessment of average Irish dairy farm

Purpose

The majority of sustainability studies of dairy farms focused on environmental performance and profitability; however, social aspect has been hardly assessed. This study aims to investigate the social impacts of dairy farm via a case study using a social life cycle assessment framework.

Methods

The assessment was carried out applying the social LCA Guideline by UNEP-SETAC. Nineteen suitable social indicators were selected from four stakeholder categories of the guideline. Characterization and normalization were further developed based on data availability. National farm survey data was used as foreground data for farm activities, supplemented with background data from public database and life cycle working environment (LCWE) data by Gabi database. All indicators were divided into three groups: functional unit-related quantitative indicators, non-functional unit-related quantitative indicators and semi-quantitative indicators.

Results and discussion

Irish dairy farming has positive social impacts on value chain actors and society, predominantly positive impacts for local community and generally positive values for workers. The main negative impacts are health and safety issue, equal opportunity for workers, and safe and healthy living conditions for the local community. Possible actions to improve the social performance include introducing more efficient and robotic milk production systems; applying better handling methods and using real time decision support to operational management for emissions reduction.

Conclusions

This study is the first attempt of social LCA in Ireland. It demonstrated a possible method to carry out SLCA for Irish dairy sector. The results identified the positive and negative social hotspot of dairy farm with recommendation for future improvement.

     

Hotspot identification in the clothing industry using social life cycle assessment—opportunities and challenges of input-output modelling

Purpose

A cradle-to-gate, input/output-based social life cycle assessment (SLCA) was conducted using the Swedish clothing consumption as a case study. The aim was to investigate the influence of the cut-off rule and the definition of “hotspots” in social hotspot assessment. A second aim was to identify social hotspots of Swedish clothing on a national level.

Methods

The case study was based on the SLCA methodology provided in the Guidelines for Social Life Cycle Assessment of Products (Benoît and Mazijn 2009). An input/output model was used to define the product system from cradle to gate. The negative social hotspots were evaluated for a set of social indicators that were selected by consumers. The impact assessment was conducted on a sector and country level by using the Social Hotspots Database. The identified sectors of the economy with high and very high levels of risk were listed for each social indicator.

Results and discussion

The results pinpointed some hotspots throughout the supply chain for Swedish clothing consumption. Some unexpected sectors such as commerce and business services in Bangladesh were identified as important hotspots as well as main sectors in the production phase such as plant fibres, textiles and garments that would be expected also on the bases of a traditional process analysis. A sensitivity analysis on different cut-off values showed the extent to which the choice of cut-off rule can directly affect the results via influence over the number of country-specific sectors (CSSs) in the product system. The influence of the hotspot definition was investigated by evaluating the working hour intensity for low- and medium-risk levels for three different indicators. The results show that for child labour, 92 % of the share of working hours was associated with low- and medium-risk levels. Therefore, the evaluation of risk levels other than high and very high can provide a more complete picture of the hotspots.

Conclusions

The application of input/output-based SLCA on the clothing production supply chain provided a more complete picture of the social hotspots than with traditional process-based SLCA. Some unexpected sectors related to commerce and business appeared as social hotspots in the clothing industry. The study explored some important parameters in applying an input/output-based SLCA. The results show that the cut-off values and definition of hotspots in relation to risk levels can directly influence the results.

     

In search of income reference points for SLCA using a country level sustainability benchmark (part 1): fair inequality. A contribution to the Oiconomy project

Purpose

This paper is part 1 of our twin articles on income reference points for Social Life Cycle Assessment (SLCA). Preventative costs based LCA systems, such as the EcoCost system and the Oiconomy system, need targets (performance reference points) to determine the marginal preventative costs, the costs of the most expensive measure that globally needs to be employed to reach the target. To extend the EcoCost system for social issues, targets are required for issues like fair wages and fair inequality of wages, issues for which no agreed standard, no effect level or target exists. One way of setting targets is to take best practices as benchmark, e.g. the practices of a group of best performing countries. The purpose of this part 1 article is to first develop a well-founded benchmark group of the 20 % best performing countries and thereafter propose a well-founded target for the issue of inequality for preventative costs based SLCA, which can also serve as performance reference point for SLCA in general and for other uses. In part 2, for the same purposes and using the same benchmark group, we propose targets for fair minimum wages for every country.

Methods

A benchmark group of countries for the setting of targets was determined by an assessment of available country performance indicators, based on 5 criteria. Thereafter, we derived a proposal for a maximum inequality ratio based on existing democratically determined inequality ratios in the benchmark group.

Results and discussion

The Sustainable Society Index–Human Wellbeing proved the best indicator for a country benchmark for preventative cost-based SLCA. Using the average of maximum democratically determined income differences in a benchmark group of countries determined by this index, a performance reference point for SLCA for the issue of fair inequality was derived and proposed, resulting in a maximum ratio of income differences for governmental institutions of 14.1, for government ruled companies of 18.3 and for industry of a factor 23.8.

Conclusions

It proved possible to derive a target for maximum inequality of wages, based on democratic choices in a benchmark group of the 20 % best performing countries. The target for governmental institutions may be called objective, and proposed augmentations for government ruled companies and industry, though value choices, seem reasonable for the consumer who requires prevention of all possible harm as consequence of his purchase choices and who, as a voter, contributes to governmental standards.

     

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.

     

Social life cycle assessment of first and second-generation ethanol production technologies in Brazil

Purpose

The main goal of this study is to suggest quantitative social metrics to evaluate different sugarcane biorefinery systems in Brazil by exploring a novel hybrid approach integrating social life cycle assessment and input-output analysis.

Methods

Social life cycle assessment is the main methodology for evaluating social aspects based on a life-cycle approach. Using this framework, a hybrid model integrating social life cycle assessment and input-output analysis was introduced to evaluate different social effects of biorefinery scenarios considering workers as the stakeholder category. Job creation, occupational accidents, wage profile, education profile, and gender profile were selected as the main inventory indicators. A case study of three scenarios considering variations in agricultural and industrial technologies (including sugarcane straw recovery and second-generation ethanol production, for instance) was carried out for evaluating present first-generation (1G-basic, 1G-optimized) and future first- and second-generation ethanol production (1G2G).

Results and discussion

The 1G-basic scenario leads to higher job creation levels over the supply chain mainly because of the influence of agricultural stage whose workers are mostly employed in sugarcane manual operations. On the other hand, 1G-optimized and 1G2G present supply chains are more reliant on the manufacturing, trade, and services sectors whose workers are associated with a lower level of occupational accidents, higher average wages, higher education level, and more participation of women in the work force.

Conclusions

The use of a novel hybrid approach integrating social life cycle assessment (SLCA) and input-output analysis (IOA) was useful to quantitatively distinguish the social effects over different present and future sugarcane biorefinery supply chains. As a consequence, this approach is very useful to support decision-making processes aiming to improve the sustainability of sugarcane biorefineries taking social aspects into account.

     

From behind the curtain: talking about values in LCA

Purpose

Practitioners of life cycle assessment (LCA) acknowledge that more input from social scientists can help advance the cause of life cycle management (LCM). This commentary offers a social science perspective on a long-running question within LCA, namely, how the field should manage not only stakeholders’ values but also those of practitioners themselves.

Methods

More than 60 interviews were conducted with LCA practitioners and their industry clients. Qualitative data were also collected through participant observation at several LCA and LCM conferences, a study of the field’s history, and extensive content and discourse analysis of LCA publications and online forums.

Results and discussion

Results show that LCA practitioners’ values are informed partly by the knowledge acquired through their LCA work. At the same time, LCA standards and professional norms implicitly advise practitioners to keep those values out of their work as much as possible, so as not to compromise its apparent objectivity. By contrast, many social scientists contend openly that value-based judgments, based on “situated knowledge,” can actually enhance the rigor, accountability, and credibility of scientific assessments.

Conclusions

LCA practitioners’ own situated knowledge justifies not only the value choices required by LCA but also their evaluative judgments of contemporary life cycle-based sustainability initiatives. This more critical voice could advance the goals of LCM while also boosting the credibility of LCA more generally.

     

An analytic framework for social life cycle impact assessment—part 1: methodology

Purpose

This study aims to develop a new framework of social life cycle impact assessment (SLCIA) method based on the United Nations Environment Program/Society of Environmental Toxicology and Chemistry (UNEP/SETAC) Guidelines for analyzing the social impact in Taiwan, particularly in the electronics industry.

Methods

After reviewing the literature on social life cycle assessment (SLCA), we analyzed existing case studies and developed SLCIA methods based on the UNEP/SETAC Guidelines. We thereafter identified stakeholders, subcategories, and indicators in accordance with the current status of SLCA case studies and opinions from ten experts in the Taiwanese electronics industry. Both quantitative and semi-quantitative indicators were subsequently proposed to assess the social impact of workers in the Taiwanese electronics sector. Each indicator was given the score of 1 to 5 by classifying the social impact percentage of nine scales. To formulate an analytic framework for SLCIA, the weighting values of each subcategory and indicator were determined using the consistent fuzzy preference relations (CFPR) method.

Results and discussion

Seven subcategories and 19 qualitative and quantitative indicators of worker stakeholders for the electronics sector were identified based on the UNEP/SETAC Guidelines. A score of 1 to 5 is assigned to each quantitative indicator by classifying the social impact percentage of nine scales. The data obtained from companies for each quantitative indicator were subsequently transformed into social impact percentage in terms of the statistical data on social situations at the country or industry level. With regard to semi-quantitative indicators, three implementation levels of management efforts on social performance within five elements were identified. The CFPR method was then employed to determine the weights of each indicator by ten experts. Results indicated that preventing forced work practices, protecting children from having to work, and providing minimum and fair wages for workers are the three most important indicators for assessing social impact.

Conclusions

A new SLCIA method that incorporates both quantitative and semi-quantitative indicators was proposed for assessing social impact in the electronics sector in Taiwan. Nine quantitative indicators can be easily organized using available social data from government statistics as performance reference points (PRPs) to determine the social impact exerted by companies. The relative weights were determined to allow for an impact assessment and thus solve the limitation of their currently assumed equal weights. The proposed framework is examined to analyze the social impact of three production sites for semiconductor packaging and manufacturing in Taiwan.

     

A lost opportunity for science: journals promote data sharing in metabolomics but do not enforce it

Introduction

Data sharing is being increasingly required by journals and has been heralded as a solution to the ‘replication crisis’.

Objectives

(i) Review data sharing policies of journals publishing the most metabolomics papers associated with open data and (ii) compare these journals’ policies to those that publish the most metabolomics papers.

Methods

A PubMed search was used to identify metabolomics papers. Metabolomics data repositories were manually searched for linked publications.

Results

Journals that support data sharing are not necessarily those with the most papers associated to open metabolomics data.

Conclusion

Further efforts are required to improve data sharing in metabolomics.

     

Pseudo current density maps of electrophysiological heart,nerve or brain function and their physical basis

Background

In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular.

Methods

The physical basis of these intuitive maps is clarified by means of analytically solvable problems.

Results

Examples in magnetocardiography, magnetoencephalography and magnetoneurography demonstrate the usefulness of this method.

Conclusion

Hardware realizations of the HC-transformation and some similar transformations are discussed which could advantageously support cross-platform comparability of biomagnetic measurements.

     

Untargeted metabolomics suffers from incomplete raw data processing

Introduction

Untargeted metabolomics is a powerful tool for biological discoveries. To analyze the complex raw data, significant advances in computational approaches have been made, yet it is not clear how exhaustive and reliable the data analysis results are.

Objectives

Assessment of the quality of raw data processing in untargeted metabolomics.

Methods

Five published untargeted metabolomics studies, were reanalyzed.

Results

Omissions of at least 50 relevant compounds from the original results as well as examples of representative mistakes were reported for each study.

Conclusion

Incomplete raw data processing shows unexplored potential of current and legacy data.

     

Metabolomic profiling of maternal hair suggests rapid development of intrahepatic cholestasis of pregnancy

Introduction

Intrahepatic cholestasis of pregnancy (ICP) is a common maternal liver disease; development can result in devastating consequences, including sudden fetal death and stillbirth. Currently, recognition of ICP only occurs following onset of clinical symptoms.

Objective

Investigate the maternal hair metabolome for predictive biomarkers of ICP.

Methods

The maternal hair metabolome (gestational age of sampling between 17 and 41 weeks) of 38 Chinese women with ICP and 46 pregnant controls was analysed using gas chromatography–mass spectrometry.

Results

Of 105 metabolites detected in hair, none were significantly associated with ICP.

Conclusion

Hair samples represent accumulative environmental exposure over time. Samples collected at the onset of ICP did not reveal any metabolic shifts, suggesting rapid development of the disease.

     

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.