Life cycle management of energy-consuming products in companies using IO-LCA

Background, aim, and scope

Today, the effective integration of life cycle thinking into existing business routines is argued to be the most critical step for more sustainable business models. The study tests the suitability of an input–output life cycle assessment (IO-LCA) approach in screening life cycle impacts of energy-using products in companies. It estimates the life cycle impacts of three products and assesses the suitability of such approach in a company environment.

Materials and methods

The multiple case studies evaluate the suitability of an IO-LCA method in a company environment. A comprehensive life cycle cost and impact study of three product systems (building ventilation system, information and communication technology (ICT) network product, and welding machine) is conducted and the life cycle phases with highest economical and environmental contribution are determined. Scenario analysis is performed in order to assess the sensitivity of the results to major changes in the studied systems. Finally, the usability of the IO-LCA approach for environmental evaluations in companies is assessed by collecting data on workload and interviewing the participating workers and managers.

Results

The results showed that the use phase with operating energy was environmentally important in all evaluated energy-using products. However, only in one case (ICT network product) the use was the single most significant life cycle phase. In two other cases, the sourcing was equally important. The results also indicated that the IO-LCA approach is much easier to adapt by current management of companies because it automatically links life cycle costs to environmental indicators and, by order of magnitude, reduces the workload in companies.

Discussion

It appears that the IO-LCA approach can be used to screen environmentally significant life cycle phases of energy-using products in companies by utilizing readily available accounting or other documented data. The IO-LCA approach produced comparable results with the ones published in traditional process-based LCA literature. In addition to the main results, some practical benefits of using the IO-LCA could also be suggested: the approach was very fast to use and would thus allow an easier adoption of environmental evaluations in companies as well as wider environmental testing of products in early conceptual design phase.

Conclusions

The results indicated that the IO-LCA approach could clearly offer added value to the environmental management of companies. The IO-LCA was found to provide a very fast access to the key life cycle characteristics of products. Similarly, it offered practical means to integrate life cycle thinking into existing business routines and to activate the decision makers in companies by giving them easily comprehendible results.

Recommendations and perspectives

The results would suggest that similar environmental IO tables, besides the US ones used here, would have value and should be collected for other major geographical and economical regions. The tables would enable a much larger share of companies to manage their environmental issues. It also seems that, because the user profile is so dominant in the case of energy-using products, more studies, both theoretical (How to valuate the future behavior in environmental studies?) and empirical (What really creates value for users?), should focus on the behavior of users.

     

Life cycle assessment-based selection of a sustainable lightweight automotive engine hood design

Purpose

This study presents a life cycle assessment (LCA)-based sustainable and lightweight automotive engine hood design and compares the life cycle energy consumption and potential environmental impacts of a steel (baseline) automotive engine hood with three types of lightweight design: advanced high strength steel (AHSS), aluminum, and carbon fiber.

Methods

A “cradle-to-grave” LCA including the production, use, and end-of-life stages is conducted in accordance with the ISO 14040/14044 standards. Onsite data collected by Chinese automotive companies in 2015 are used in the assessment. The Cumulative Energy Demand v1.09 method is applied to evaluate cumulative energy demand (CED), and the International Panel on Climate Change 2013 100a method is used to estimate global warming potential (GWP 100a).

Results and discussion

Among the different lightweight designs for the engine hood, the aluminum design is the most sustainable and has the lowest CED and GWP (100a) from a life cycle perspective, which is based on a lifetime driving distance of approximately 150,000 km. In addition, the AHSS design is also sustainable and lightweight. The carbon fiber design results in higher CED and GWP (100a) values than the steel (baseline) design during the life cycle but results in the largest CED and GWP (100a) savings through waste material recycling. The AHSS design exhibits the best break-even distance based on CED and GWP (100a) within 150,000 km.

Conclusions

Sensitivity analysis results show that the lifetime driving distance and material recycling rate have the largest impacts on the overall CEDs and GWPs of the three lightweight designs.

     

Life cycle assessment and life cycle costing of road infrastructure in residential neighbourhoods

Purpose

The built environment consists of a huge amount of infrastructure, such as roads and utilities. The objective of this paper is to assess the life cycle financial and environmental impact of road infrastructure in residential neighbourhoods and to analyse the relative contribution of road infrastructure in the total impact of neighbourhoods.

Methods

Various road sections are analysed based on an integrated life cycle approach, combining life cycle costing and life cycle assessment. To deal with complexity, a hierarchic assessment structure, using the principles of the “element method for cost control”, is implemented. Four neighbourhood models with diverse built densities are compared to gain insight in the relative impact of road infrastructure in neighbourhoods.

Results and discussion

The results reveal important financial and environmental impact differences between the road sections analysed. Main contributors to the life cycle financial and environmental impact are the surface layer and electrical and piped services. The contribution of road infrastructure to the total neighbourhood impact, ranging from 2 to 9 % of the total cost, is relatively limited, compared to buildings, but not negligible in low built density neighbourhoods.

Conclusions

Good spatial planning of the neighbourhood is recommended to reduce the amount of road infrastructure and the related financial and environmental impact. The priority should be to design denser neighbourhood layouts, before decreasing the financial and environmental impact of the road sections.

     

Life cycle assessment of copper production: a case study in China

Purpose

China is the world’s largest producer and consumer of refined and reclaimed copper because of the rapid economic and industrial development of this country. However, only a few studies have analyzed the environmental impact of China’s copper industry. The current study analyzes the life cycle environmental impact of copper production in China.

Methods

A life cycle impact assessment using the ReCiPe method was conducted to estimate the environmental impact of refined and reclaimed copper production in China. Uncertainty analysis was also performed based on the Monte-Carlo simulation.

Results and discussion

The environmental impact of refined copper was higher than that of reclaimed copper in almost all categories except for human toxicity because of the direct atmospheric arsenic emission during the copper recycling stage. The overall environmental impact for the refined copper production was mainly attributed to metal depletion, freshwater ecotoxicity, marine ecotoxicity, and water depletion potential impact. By contrast, that for the reclaimed copper production was mainly caused by human toxicity impact.

Conclusions

Results show that the reclaimed copper scenario had approximately 59 to 99% more environmental benefits than those of the refined copper scenario in most key categories except for human toxicity, in which a similar environmental burden was observed between both scenarios. The key factors that reduce the overall environmental impact for China’s copper industry include decreasing direct heavy metal emissions in air and water, increasing the national recycling rate of copper, improving electricity consumption efficiency, replacing coal with clean energy sources for electricity production, and optimizing the efficiency of copper ore mining and consumption.

     

A modeling framework to evaluate sustainability of building construction based on LCSA

Purpose

Life cycle sustainability assessment (LCSA) is a method that combines three life cycle techniques, viz. environmental life cycle assessment (LCA), life cycle costing (LCC), and social life cycle assessment (S-LCA). This study is intended to develop a LCSA framework and a case study of LCSA for building construction projects.

Methods

A LCSA framework is proposed to combine the three life cycle techniques. In the modeling phases, three life cycle models are used in the LCSA framework, namely the environmental model of construction (EMoC), cost model of construction (CMoC), and social-impact model of construction (SMoC). A residential building project is applied to the proposed LCSA framework from “cradle to the end of construction” processes to unveil the limitations and future research needs of the LCSA framework.

Results and discussion

It is found that material extraction and manufacturing account for over 90 % to the environmental impacts while they contribute to 61 % to the construction cost. In terms of social impacts, on-site construction performs better than material extraction and manufacturing, and on-site construction has larger contributions to the positive social impacts. The model outcomes are validated through interviews with local experts in Hong Kong. The result indicates that the performance of the models is generally satisfactory.

Conclusions

The case study has confirmed that LCSA is feasible. Being one of the first applications of LCSA on building construction, this study fulfills the current research gap and paves the way for future development of LCSA.

     

Life cycle assessment in the furniture industry: the case study of an office cabinet

Purpose

In an effort to reduce the environmental impacts of the furniture sector, this study aimed to diagnose the environmental performance of an office cabinet throughout its life cycle.

Methods

An attributional life cycle assessment (LCA) was used, based on the ISO 14044 Standard and ILCD Handbook. The scope of the study considered the entire supply chain, from cradle to grave, including the steps of pre-manufacturing, manufacturing, use, and post-use of the product. The impact assessment method was the International Reference Life Cycle Data System (ILCD) 2011 midpoint.

Results and discussion

The results identified that the most significant environmental impact of the furniture life cycle was due to the distances covered and production of the main raw material, wood medium-density particleboard (MDP). The evaluation of transport scenarios showed environmental tradeoffs for truck fuel switches and environmental gains for the distribution of MDP from closer suppliers by truck, as well as from current supplier by truck and ship in the major categories. Furthermore, evaluation of the office cabinet post-use options showed that reuse, recycling, or energy recovery from waste cause significant environmental gains in the major categories. Wooden furniture is a potential carbon sink if its life cycle does not emit more greenhouse gases than its materials can store. The impacts of substitution scenarios varied depending on the type of product avoided.

Conclusions

The LCA proved a powerful method to diagnose and manage environmental impacts in complex product systems. The sensitivity analysis showed that it is possible to reduce the environmental impacts and, at the same time, make the furniture industry increase its economic gains and net carbon stock in the anthroposphere.

     

When considering no man is an island—assessing bioenergy systems in a regional and LCA context: a review

Purpose

With many environmental burdens associated with bioenergy production occurring at the regional level, there is a need to produce more regional and spatially representative life cycle assessment of bioenergy systems. On the other hand, such assessments also need to account for the global and cumulative impacts along the full bioenergy life cycle in order to support effective regional policy measures and decision making. Therefore, the challenge is to find a balance. In other words, how should we define the regional context for bioenergy system assessments in order to complement life cycle thinking? The aim of this review is to answer this question by providing an overview of important considerations when assessing bioenergy systems in a regional and LCA context and how these two contexts intersect. It also aims to help guide and orientate LCA practitioners interested in including more regional aspects in their bioenergy studies. Until now, such a review which explores the integration of regional and life cycle contexts in relation to bioenergy systems and their products has not been done.

Methods

As a first step, we define what we mean by the term region. We then look at the potential burdens relating to bioenergy systems and their relationship with the regional context. In a next step, we explore life cycle thinking and the intersection between the regional and LCA contexts by providing some examples from the literature. We then discuss the benefits and limitations of such regionally contextualized life cycle approaches in relation to bioenergy production systems and indeed other alternative biomass uses.

Results and discussion

Three regional contexts were identified to help orientate life cycle thinking aiming to assess the regional and nonregional environmental implications of bioenergy production. These contexts were as follows: “within regional,” “regional and ROW,” and “regionalized.” The added value of implementing a regionally contextualized life cycle approach is the ability, therefore, to include greater regional and spatial details in the assessments of bioenergy production systems, without losing the links to the diversity of global supply chains. Thus, providing greater geographical and regional insight into how such potential burdens can be reduced or shifted burdens avoided or how associated regional production activities could be optimized to mitigate such burdens.

Conclusions

The use of different regional contexts as proposed in this paper is not only useful to orientate life cycle thinking in relation to bioenergy systems but also for the assessment of alternative novel bio-based systems.

     

Organizing life cycle management in practice: challenges of a multinational manufacturing corporation

Purpose

The environmental life cycle management (LCM) literature proposes many factors considered critical in order to successfully conduct LCM. This study contrasts these vague and general factors proposed as critical to LCM in existing literature, with detailed accounts of LCM in practice.

Methods

A literature review of three related research fields, i.e., LCM, life cycle thinking, and sustainable supply chain management, is contrasted with a study of how LCM is enacted in practice in a large multinational manufacturing company recognized for its LCM work. A qualitative study, with mainly a managerial focus, is conducted based on interviews, workshops, part-time observations, and document studies.

Results and discussion

The literature review demonstrates that the three related research fields provide different accounts of LCM: all apply a holistic environmental perspective, but with different emphases and using largely different research methods. The empirical study shows that integration was a common topic at the studied company and that solutions were often sought in tools and processes. Middle management support proved important, and challenging, in these integration efforts. Challenges identified also included further integrating LCM into departments such as purchasing and sales.

Conclusions

The constant focus on integration at the studied company implies that LCM work is an ongoing effort. Several integration paths are identified: (1) inclusion of sustainability aspects in tools and processes, (2) finding ways to work around certain organizational levels, and (3) using networks and social interaction to create commitment and integration. Although the concept of LCM implies a holistic approach, LCM in practice reveals a lack of a comprehensive overview of LCM-related initiatives and of involved sustainability practitioners within the studied organization.

     

On the boundary between economy and environment in life cycle assessment

Purpose

We investigate how the boundary between product systems and their environment has been delineated in life cycle assessment and question the usefulness and ontological relevance of a strict division between the two.

Methods

We consider flows, activities and impacts as general terms applicable to both product systems and their environment and propose that the ontologically relevant boundary is between the flows that are modelled as inputs to other activities (economic or environmental)—and the flows that—in a specific study—are regarded as final impacts, in the sense that no further feedback into the product system is considered before these impacts are applied in decision-making. Using this conceptual model, we contrast the traditional mathematical calculation of the life cycle impacts with a new, simpler computational structure where the life cycle impacts are calculated directly as part of the Leontief inverse, treating product flows and environmental flows in parallel, without the need to consider any boundary between economic and environmental activities.

Results and discussion

Our theoretical outline and the numerical example demonstrate that the distinctions and boundaries between product systems and their environment are unnecessary and in some cases obstructive from the perspective of impact assessment, and can therefore be ignored or chosen freely to reflect meaningful distinctions of specific life cycle assessment (LCA) studies. We show that our proposed computational structure is backwards compatible with the current practice of LCA modelling, while allowing inclusion of feedback loops both from the environment to the economy and internally between different impact categories in the impact assessment.

Conclusions

Our proposed computational structure for LCA facilitates consistent, explicit and transparent modelling of the feedback loops between environment and the economy and between different environmental mechanisms. The explicit and transparent modelling, combining economic and environmental information in a common computational structure, facilitates data exchange and re-use between different academic fields.

     

Comparative life cycle assessment and life cycle costing of lodging in the Himalaya

Purpose

The main aim of the study is to assess the environmental and economic impacts of the lodging sector located in the Himalayan region of Nepal, from a life cycle perspective. The assessment should support decision making in technology and material selection for minimal environmental and economic burden in future construction projects.

Methods

The study consists of the life cycle assessment and life cycle costing of lodging in three building types: traditional, semi-modern and modern. The life cycle stages under analysis include raw material acquisition, manufacturing, construction, use, maintenance and material replacement. The study includes a sensitivity analysis focusing on the lifespan of buildings, occupancy rate and discount and inflation rates. The functional unit was formulated as the ‘Lodging of one additional guest per night’, and the time horizon is 50 years of building lifespan. Both primary and secondary data were used in the life cycle inventory.

Results and discussion

The modern building has the highest global warming potential (kg CO_2-eq) as well as higher costs over 50 years of building lifespan. The results show that the use stage is responsible for the largest share of environmental impacts and costs, which are related to energy use for different household activities. The use of commercial materials in the modern building, which have to be transported mostly from the capital in the buildings, makes the higher GWP in the construction and replacement stages. Furthermore, a breakdown of the building components shows that the roof and wall of the building are the largest contributors to the production-related environmental impact.

Conclusions

The findings suggest that the main improvement opportunities in the lodging sector lie in the reduction of impacts on the use stage and in the choice of materials for wall and roof.

     

The EcoSpold 2 format—why a new format?

Purpose

This paper introduces the new EcoSpold data format for life cycle inventory (LCI).

Methods

A short historical retrospect on data formats in the life cycle assessment (LCA) field is given. The guiding principles for the revision and implementation are explained. Some technical basics of the data format are described, and changes to the previous data format are explained.

Results

The EcoSpold 2 data format caters for new requirements that have arisen in the LCA field in recent years.

Conclusions

The new data format is the basis for the Ecoinvent v3 database, but since it is an open data format, it is expected to be adopted by other LCI databases. Several new concepts used in the new EcoSpold 2 data format open the way for new possibilities for the LCA practitioners and to expand the application of the datasets in other fields beyond LCA (e.g., Material Flow Analysis, Energy Balancing).

     

Attributional and consequential LCA in the ILCD handbook

Purpose

This discussion article aims to highlight two problematic aspects in the International Reference Life Cycle Data System (ILCD) Handbook: its guidance to the choice between attributional and consequential modeling and to the choice between average and marginal data as input to the life cycle inventory (LCI) analysis.

Methods

We analyze the ILCD guidance by comparing different statements in the handbook with each other and with previous research in this area.

Results and discussion

We find that the ILCD handbook is internally inconsistent when it comes to recommendations on how to choose between attributional and consequential modeling. We also find that the handbook is inconsistent with much of previous research in this matter, and also in the recommendations on how to choose between average and marginal data in the LCI.

Conclusions

Because of the inconsistencies in the ILCD handbook, we recommend that the handbook be revised.

     

A life cycle comparison of disposal and beneficial use of coal combustion products in Florida

Background, Goal, and Scope

Currently, only 40%, or 44.5 million metric tons, of coal combustion products (CCPs) generated in the United States each year by electric utilities are diverted from disposal in landfills or surface impoundments and recycled. Despite promising economic and environmental savings, there has been scant attention devoted to assessing life cycle impacts of CCP disposal and beneficial use. The objective of this paper is to present a life cycle inventory considering two cases of CCP management, including the stages of coal mining and preparation, coal combustion, CCP disposal, and CCP beneficial use. Six beneficial uses were considered: concrete production, structural fills, soil amendments, road construction, blasting grit and roofing granules, and wallboard.

Methods

Primary data for raw material inputs and emissions of all stages considered were obtained from surveys and site visits of coal-burning utilities in Florida conducted in 2002, and secondary data were obtained from various published sources and from databases available in SimaPro 5.1 (PRé Consultants, Amersfoort, The Netherlands).

Results

Results revealed that 50 percent of all CCPs produced, or 108 kg per 1,000 kg of coal combusted, are diverted for application in a beneficial use; however, the relative amounts sold by each utility is dependent on the process operating parameters, air emission control devices, and resulting quality of CCP. Diversion of 50% of all CCPs to beneficial use applications yields a decrease in the total raw materials requirements (with the exception of gravel and iron) and most emissions to air, water, and land, as compared to 100% disposal.

Discussion

The greatest reduction of raw materials was attributed to replacing Portland cement with fly ash, using bottom ash as an aggregate in concrete production and road construction in place of natural materials, and substituting FGD gypsum for natural gypsum in wallboard. The use of fly ash as cementitious material in concrete also promised significant reductions in emissions, particularly the carbon dioxide that would be generated from Portland cement production. Beneficial uses of fly ash and gypsum showed reductions of emissions to water (particularly total dissolved solids) and emissions of metals to land, although these reductions were small compared to simply diverting 50% of all CCPs from landfills or surface impoundments.

Conclusions

This life cycle inventory (LCI) provides the foundation for assessing the impacts of CCP disposal and beneficial use. Beneficial use of CCPs is shown here to yield reductions in raw material requirements and various emissions to all environmental compartments, with potential tangible savings to human health and the environment.

Recommendations and Perspectives

Extension of this life cycle inventory to include impact assessment and sensitivity analysis will enable a determination of whether the savings in emissions reported here actually result in significant improvements in environmental and human health impacts.

     

Review: life cycle assessments in Nigeria,Ghana, and Ivory Coast

Purpose

Life cycle assessments (LCAs) are considered common quantitative environmental techniques to analyze the environmental impact of products and/or services throughout their entire life cycle. A few LCA studies have been conducted in West Africa. This study aimed to discuss the availability of LCA (and similar) studies in Nigeria, Ghana, and Ivory Coast.

Methods

An online literature review of reports published between 2000 and 2016 was conducted using the following keywords: “life cycle assessment,” “carbon footprinting,” “water footprinting,” “environmental impact,” “Nigeria,” “Ghana” and “Ivory Coast.”

Results and discussion

A total of 31 LCA and environmental studies in Nigeria, Ghana, and Ivory Coast were found; all but one were conducted after 2008. These were mainly academic and most were publicly available. The industries studied included energy sector, waste management, real estate, food sector, and others such as timber and gold. The minimal number of studies on LCAs and environmental impacts in these West African states could be because companies are failing to promote quantitative environmental studies or studies are kept internally for the use of other assessment techniques. Furthermore, it could be that academic research institutions lack cutting-edge research resources for LCA, environmental impact, carbon, and water footprinting studies.

Conclusions

Further quantitative environmental studies should be conducted in Nigeria, Ghana, and Ivory Coast to increase the understanding of environmental impacts. In these countries, the existence of LCA studies (and by association the localized life cycle inventory (LCI) datasets) is crucial as more companies request this information to feed into background processes.

     

Opportunities and challenges of implementing life cycle assessment in seafood certification: a case study for Spain

Purpose

Eco-labelling has become part of the business strategy of companies thanks to numerous advantages in terms of engaging with consumers and gaining market quota. The aim of this article is to present a critical discussion on the development and implementation of a new eco-label named pescaenverde, registered in Spain, as the first type III eco-label in the Spanish fishing sector that is based on life cycle approaches for seafood products.

Methods

More specifically, it aims to complement ecosystem-based eco-labels with the computation of the carbon footprint and the energy return on investment (EROI) of seafood products. Furthermore, it proposes to discuss the ecological criteria, certification process or the opportunities and challenges of the market implementation of this eco-label in detail. Finally, the authors argue that life cycle eco-labels should be considered important complements for more specific sector- or ecosystem-oriented labels already in use, rather than direct competitors.

Results and discussion

There has been much criticism towards the eco-labelling sector as regards the transparency and scientific rigour of its standards. The fishing and seafood sector, which has experienced a boom in eco-labelling in recent years, due mainly to the strength of the Marine Stewardship Council certification scheme, is not alien to this controversy, since critics advocate expanding the concept of sustainable fisheries beyond an ecosystem approach in order to account for global environmental concerns such as greenhouse gas (GHG) emissions or energy use. Not surprisingly, the European Union and other authorities currently encourage eco-labels to base their ecological criteria on life cycle approaches. Therefore, the current study discusses the ecological criteria, certification process or the opportunities and challenges of the market implementation of this eco-label in detail.

Conclusions

The specificity of the life cycle inventory scheme used in pescaenverde delivers an accurate computation of environmental impacts for the specific case of Spanish fisheries. However, the geographical expansion of this scheme to other nations or regions will be conditioned by an important software adaptation to the particular inventory characteristics of the new fisheries, fleets and products.

Recommendations

Adapting ecological criteria to other situations would also need substantial discussion, since the use of this certification scheme is not intended to contrast or compare seafood products against each other but to provide consumers with an easily identifiable label through which they can detect environmentally sustainable practices in terms of GHG emissions and energy use in the fishing fleets supporting the seafood products purchased.

     

Life cycle assessment of ocean energy technologies

Purpose

Oceans offer a vast amount of renewable energy. Tidal and wave energy devices are currently the most advanced conduits of ocean energy. To date, only a few life cycle assessments for ocean energy have been carried out for ocean energy. This study analyses ocean energy devices, including all technologies currently being proposed, in order to gain a better understanding of their environmental impacts and explore how they can contribute to a more sustainable energy supply.

Methods

The study followed the methodology of life cycle assessment including all life cycle steps from cradle to grave. The various types of device were assessed, on the basis of a functional unit of 1 kWh of electricity delivered to the grid. The impact categories investigated were based on the ILCD recommendations. The life cycle models were set up using detailed technical information on the components and structure of around 180 ocean energy devices from an in-house database.

Results and discussion

The design of ocean energy devices still varies considerably, and their weight ranges from 190 to 1270 t, depending on device type. Environmental impacts are closely linked to material inputs and are caused mainly by mooring and foundations and structural components, while impacts from assembly, installation and use are insignificant for all device types. Total greenhouse gas emissions of ocean energy devices range from about 15 to 105 g CO₂-eq. kWh^?1. Average global warming potential for all device types is 53?±?29 g CO₂-eq. kWh^?1. The results of this study are comparable with those of other studies and confirm that the environmental impacts of ocean energy devices are comparable with those of other renewable technologies and can contribute to a more sustainable energy supply.

Conclusions

Ocean energy devices are still at an early stage of development compared with other renewable energy technologies. Their environmental impacts can be further reduced by technology improvements already being pursued by developers (e.g. increased efficiency and reliability). Future life cycle assessment studies should assess whole ocean energy arrays or ocean energy farms.

     

Life cycle assessment of the environmental influence of wooden and concrete utility poles based on service lifetime

Purpose

Many applications of life cycle assessment do not consider the variability of the service lifetime of different structures, and this may be a relevant factor in an environmental impact assessment. This paper aims to determine the influence of the service lifetime on the potential environmental impacts of wooden and concrete poles in the electricity distribution system.

Methods

The estimation of service lifetime was conducted using the factorial method. The life cycle assessment was applied using SimaPro software and considered the entire life cycle of utility poles, from the extraction of raw materials to the final disposal. Then, an evaluation of the environmental impacts using the CML IA baseline method was performed. The study included the analysis of uncertainty using the Monte Carlo method.

Results and discussion

In general, the wooden poles had a lower potential environmental impact compared to the concrete poles. The result of the sensitivity analysis considering the variability of the chromated copper arsenate wood preservative retention rate suggests that the frequency of maintenance affects the service lifetime. Often, the comparison of products in the LCA perspective is carried out by considering similar useful lifetime services for the different alternatives, and this study shows that the environmental performance of products or services is directly proportional to the lifetime. It is a crucial parameter that has to be clarified in order to reduce uncertainty in the results.

Conclusions

Thus, some factors such as material quality, design adjustments and routine maintenance extend the service lifetime of a product or process and are shown to be effective ways to reduce environmental impacts. Therefore, the service lifetime has a significant influence on the development of the life cycle assessment. Comparative LCA studies are often sensitive to parameters that may even change the ranking of selected impact categories. All in all, from the sensitivity analysis highlighted in this study, the variability of lifetime service has proven to be one of the most prominent factors influencing comparative LCA results.

     

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.

     

LCA and LCC of the world’s longest pier: a case study on nickel-containing stainless steel rebar

Purpose

Built in 1941, the Progreso Pier was the first concrete structure in the world built with nickel-containing stainless steel reinforcement. The Pier has been in service for over 70 years without any significant repair or maintenance activities. The aim of this study was to understand the environmental and economic implications of selecting nickel-containing stainless steel reinforcement using the Progreso Pier as the case study.

Methods

A combined environmental life cycle assessment (LCA) and life cycle costing (LCC) study was conducted. The analysis considered the potential environmental impacts and the net present cost of the stainless steel reinforced structure from cradle to grave and compared it to the same structure using conventional carbon steel.

Results and discussion

The results indicated that while using stainless steel reinforcement resulted in a marginally higher environmental impact after initial construction, this is offset by the increased service life and, hence, less frequent maintenance and reconstruction activities. Relative to the as-built stainless steel reinforcement design, the environmental impacts of the carbon steel reinforced design are between 69 and 79 % higher over the analysis period. Similar observations were made for the other investigated impact categories. The cost implications of using stainless steel reinforcement show economic benefits that are complementary to the environmental benefits. Similar to the LCA, the service life benefits outweigh the higher unit costs for stainless steel, assuming a discount rate of 0.01 % as the baseline scenario. The carbon steel reinforced design has a net present cost that is 44 % higher than the as-built stainless steel reinforcement design. The crossover point for the two designs occurs at year 50, which corresponds to the reconstruction activity. A sensitivity analysis shows that the results and conclusions are sensitive to the choice in discount rate: Rates 3 % and lower produce net present costs that are lower for the as-built design; rates 4 % and higher produce net present costs that are lower for the alternative design.

Conclusions

The study demonstrates how LCA and LCC are complementary tools that can be used in decision-making for sustainable construction. The Progreso Pier exemplifies the importance of considering the entire life cycle with service life and recycling as well as long-term life cycle impacts of infrastructure projects from an environmental and economic perspective.

     

LCA applied to nano scale zero valent iron synthesis

Purpose

Application of zero valent iron nanoparticles is an innovative technology for ground water treatment and soil remediation. There are several methods to synthesise nano scale zero valent iron (nZVI), namely through bottom-up methods which consists on chemical reactions using strong reducing agents. In this work, the environmental impacts and costs were determined for two methods, namely the traditional one that uses sodium borohydride and the green method that uses extracts obtained from natural products.

Methods

The consideration of environment and economic aspects in the earlier stages of the synthesis processes and in the development of new materials is of great importance since it can help to decide if alternative methods are promising and should be further developed aiming more sustainable processes. In this work, life cycle assessment (LCA) was used as an ecodesign strategy evaluating environmental performance of the two synthesis methods, identifying critical stages of the synthesis processes of nZVI. An economic evaluation and a sensitivity analysis considering a different scenario for electricity production were also performed.

Results and discussion

The results obtained in this study showed that the green synthesis method presents lower environmental impacts than the traditional one, roughly 50% lower in the first scenario. In the second scenario, environmental impact of green synthesis corresponds to 38% of the environmental impact of traditional synthesis. In the green method, the critical stage is the extraction process which is closely related to the electricity production. In the traditional method, the reactant use is the critical stage that is related to the production of sodium borohydride. The economic evaluation indicated that the traditional synthesis method is much more expensive than the green synthesis (roughly eight times higher).

Conclusions

From the results obtained, it is possible to conclude that the green synthesis method presents lower environmental impacts in both scenarios and lower costs than the traditional synthesis.