Life Cycle Assessment Impact Categories Research Articles

Toxicological risk at workplace and toxicity as Life Cycle Assessment impact category: Substitution of solvents as an example.

Substitution of hazardous substances against less hazardous ones is a central requirement of the European Chemical Regulation REACH (European Regulation 1907/2006/EC). Hazardous substances emitted from products may not only affect the worker; drift off and distribution in the environment may finally result in exposure of the general population. This potential threat to health is covered by the impact category “toxicity” in Life Cycle Assessments. In this paper, we present a case of a substitution of volatile organic compounds in a reactive varnish, and compare the “old” formulation with the “new” formulation against health risk to the worker, and concerning the Life Cycle Assessment impact category “toxicity”. The “old” formulation contained Naphtha (petroleum), hydrodesulfurized, heavy and Solvent naphtha (petroleum), light, aromatic. In the new formulation, both naphthas were replaced by n-Butylacetate, 1-Ethoxy-2-propyl acetate and Ethyl-3-ethoxy propionate. In the European Union, the naphthas are classified as mutagens and carcinogens category 1, officially. However, if benzene is below 0.1 %, registrants in the EU proposed to omit this classification, and todays naptha products on the market obviously have benzene contents below 0.1 %. On a first glance, the improvement for workplace safety introduced by the substitution, therefore, is comparatively small, as it is for toxicity in Life Cycle Assessment. However, when background knowledge concerning chemical production processes of naphtha is included, benzene below a content of 0.1 % needs to be taken into consideration, and the benefit of substitution is more obvious.

A proposal to measure absolute environmental sustainability in life cycle assessment

Environmental monitoring indicates that progress towards the goal of environmental sustainability in many cases is slow, non-existing or negative. Indicators that use environmental carrying capacity references to evaluate whether anthropogenic systems are, or will potentially be, environmentally sustainable are therefore increasingly important. Such absolute indicators exist, but suffer from shortcomings such as incomplete coverage of environmental issues, varying data quality and varying or insufficient spatial resolution. The purpose of this article is to demonstrate that life cycle assessment (LCA) can potentially reduce or eliminate these shortcomings.We developed a generic mathematical framework for the use of carrying capacity as environmental sustainability reference in spatially resolved life cycle impact assessment models and applied this framework to the LCA impact category terrestrial acidification. In this application carrying capacity was expressed as acid deposition (eq.molH+ha−1year−1) and derived from two complementary pH related thresholds. A geochemical steady-state model was used to calculate a carrying capacity corresponding to these thresholds for 99,515 spatial units worldwide. Carrying capacities were coupled with deposition factors from a global deposition model to calculate characterisation factors (CF), which expresses space integrated occupation of carrying capacity (hayear) per kg emission. Principles for calculating the entitlement to carrying capacity of anthropogenic systems were then outlined, and the logic of considering a studied system environmentally sustainable if its indicator score (carrying capacity occupation) does not exceed its carrying capacity entitlement was demonstrated. The developed CFs and entitlement calculation principles were applied to a case study evaluating emission scenarios for personal residential electricity consumption supplied by production from 45 US coal fired electricity plant.Median values of derived CFs are 0.16–0.19hayearkg−1 for common acidifying compounds. CFs are generally highest in Northern Europe, Canada and Alaska due to the low carrying capacity of soils in these regions. Differences in indicator scores of the case study emission scenarios are to a larger extent driven by variations in pollution intensities of electricity plants than by spatial variations in CFs. None of the 45 emission scenarios could be considered environmentally sustainable when using the relative contribution to GDP or the grandfathering (proportionality to past emissions) valuation principles to calculating carrying capacity entitlements. It is argued that CFs containing carrying capacity references are complementary to existing CFs in supporting decisions aimed at simultaneously reducing environmental impacts efficiently and maintaining or achieving environmental sustainability.We have demonstrated that LCA indicators can be modified from being relative to being absolute indicators of environmental sustainability. Further research should focus on quantifying uncertainties related to choices in indicator design and on reducing uncertainties effectively.

Area of concern: a new paradigm in life cycle assessment for the development of footprint metrics

As a class of environmental metrics, footprints have been poorly defined, have shared an unclear relationship to life cycle assessment (LCA), and the variety of approaches to quantification have sometimes resulted in confusing and contradictory messages in the marketplace. In response, a task force operating under the auspices of the UNEP/SETAC Life Cycle Initiative project on environmental life cycle impact assessment (LCIA) has been working to develop generic guidance for developers of footprint metrics. The purpose of this paper is to introduce a universal footprint definition and related terminology as well as to discuss modelling implications. The task force has worked from the perspective that footprints should be based on LCA methodology, underpinned by the same data systems and models as used in LCA. However, there are important differences in purpose and orientation relative to LCA impact category indicators. Footprints have a primary orientation toward society and nontechnical stakeholders. They are also typically of narrow scope, having the purpose of reporting only in relation to specific topics. In comparison, LCA has a primary orientation toward stakeholders interested in comprehensive evaluation of overall environmental performance and trade-offs among impact categories. These differences create tension between footprints, the existing LCIA framework based on the area of protection paradigm and the core LCA standards ISO14040/44. In parallel to area of protection, we introduce area of concern as the basis for a universal footprint definition. In the same way that LCA uses impact category indicators to assess impacts that follow a common cause-effect pathway toward areas of protection, footprint metrics address areas of concern. The critical difference is that areas of concern are defined by the interests of stakeholders in society rather than the LCA community. In addition, areas of concern are stand-alone and not necessarily part of a framework intended for comprehensive environmental performance assessment. The area of concern paradigm is needed to support the development of footprints in a way that fulfils their distinctly different purpose. It is also needed as a mechanism to extricate footprints from some of the provisions of ISO 14040/44 which are not considered relevant. Specific issues are identified in relation to double counting, aggregation and the selection of relevant indicators. The universal footprint definition and related terminology introduced in this paper create a foundation that will support the development of footprint metrics in parallel with LCA.

Including pathogen risk in life cycle assessment: the effect of modelling choices in the context of sewage sludge management

Purpose: Recent attempts to include adverse effects of pathogens on human health in life cycle assessment (LCA) have focused on integrating results obtained through quantitative microbial risk assessment (QMRA) as an impact category in LCA. This study aimed to investigate whether the use of QMRA can be an adequate way of integrating pathogen impact potential in LCA and to quantify how pathogen impact potential is affected by choices regarding model structure and mathematical relationships used. Methods: This study was performed for the context of sewage sludge management and is based on pathogen concentrations in treated sludge reported in the literature. Eight reference pathogens were included in order to address important microbial groups. The pathogen impact potential associated with land application of sewage sludge was quantified based on a QMRA model for eight distinct exposure pathways. The modelling choices investigated were linearisation of dose-response and severity assessment and different modelling approaches and parameter choices in fate and exposure assessment. Results and discussion: The linearisation of effect and severity assessment had a minor impact on the results for exposure pathways where pathogen doses were low but had a major impact where pathogen doses were high. The assumptions regarding fate and exposure conditions, such as pathogen decay time, number of individuals exposed and frequency of exposure, had a significant effect on overall pathogen impact potential. If pathogen impact potential is to be integrated in LCA, a range of different parameterisations for each exposure event may be warranted rather than only the one with the highest risk per individual exposed as commonly reported for QMRAs. This is also in line with the ordinary LCA practice of focusing on average rather than extreme conditions. Conclusions: This study suggests that the use of QMRA can be an adequate way of integrating adverse effects of pathogens on human health in LCA. However, analysts should be careful when choosing model parameters such as the number of people exposed or the frequency of exposure, as LCA may require a different parameterisation than an ordinary risk assessment (RA). Therefore, a direct integration of the results of a QMRA study into LCA may be problematic. Also, in order to avoid potential bias, analysts should carefully consider whether or not pathogen impact potential and human toxicity potential need to be estimated based on a similar set of exposure pathways.

Using the planetary boundaries framework for setting impact-reduction targets in LCA contexts

The planetary boundaries (PBs) framework suggests global limits for environmental interventions which could be used to set global goals for reducing environmental impacts. This paper proposes a procedure for using such global goals for setting impact-reduction targets at the scale of products for use, for example, in life cycle assessment (LCA) contexts, e.g. as a basis for evaluating the potential of interventions to reduce the environmental impact of products. The procedure consists of four steps: (i) identifying the PBs quantified in literature that correspond to an impact category which is studied in the product assessment context in question; (ii) interpreting what the identified PBs imply in terms of global impact-reduction targets; (iii) translating the outcome of (ii) to reduction targets for the particular global market segment to which the studied product belongs; and (iv) translating the outcome of (iii) to reduction targets for the studied product. The procedure requires some assumptions and value-based choices—the influence of these is tested by applying the procedure in a specific LCA context: a study of Swedish clothing consumption. The application of the procedure in an LCA context suggested the need for eliminating all or nearly all impact of Swedish clothing consumption for most impact categories. Thus, it is improbable that a single type of impact-reduction intervention (e.g. technological development or changed user behaviour) is sufficient. The outcome’s strong dependence on impact category suggests that the procedure can help in prioritising among impact categories. Furthermore, the outcome exhibited a strong dependence on the chosen method for allocating the globally allowed impact between regions—this was tested by applying different principles identified in a literature review on the allocation of emissions rights. The outcome also strongly depended on the geographical scope—this was tested by changing the geographical scope from Sweden to Nigeria. The proposed procedure is feasible to use for LCA practitioners and other environmental analysts, and data is available to apply the procedure in contexts with different geographical scopes. Value-based choices are, however, unavoidable and significantly influence the outcome, which accentuates the subjectivity and potentially controversial nature of allocating a finite impact space to certain regions, market segments and products. How to match PBs with appropriate LCA impact categories is an important area for future research.

Geopolitical-related supply risk assessment as a complement to environmental impact assessment: the case of electric vehicles

Introducing a geopolitical-related supply risk (GeoPolRisk) into the life cycle sustainability assessment (LCSA) framework adds a criticality aspect to the current life cycle assessment (LCA) framework to more meaningfully address direct impacts on Natural Resource AoP. The weakness of resource indicators in LCA has been the topic of discussion within the life cycle community for some time. This paper presents a case study on how to proceed towards the integration of resource criticality assessment into LCA under the LCSA. The paper aims at highlighting the significance of introducing the GeoPolRisk indicator to complement and extend the established environmental LCA impact categories. A newly developed GeoPolRisk indicator proposed by Gemechu et al., J Ind Ecol (2015) was applied to metals used in the life cycle of an electric vehicle, and the results are compared with an attributional LCA of the same resources. The inventory data is based on the publication by Hawkins et al., J Ind Ecol 17:53–64 (2013), which provides a current, transparent, and detailed life cycle inventory data of a European representative first-generation battery small electric vehicle. From the 14 investigated metals, copper, aluminum, and steel are the most dominant elements that pose high environmental impacts. On the other hand, magnesium and neodymium show relatively higher supply risk when geopolitical elements are considered. While, the environmental indicator results all tend to point the same hotspots which arise from the substantial use of resources in the electric vehicle’s life cycle, the GeoPolRisk highlights that there are important elements present in very small amounts but crucial to the overall LCSA. It provides a complementary sustainability dimension that can be added to conventional LCA as an important extension within LCSA. Resource challenges in a short-term time perspective can be better addressed by including social and geopolitical factors in addition to the conventional indicators which are based on their geological availability. This is more significant for modern technologies such as electronic devices in which critical resources contribute to important components. The case study advances the use of the GeoPolRisk assessment method but does still face certain limitations that need further elaboration; however, directions for future research are promising.

Comparative Life Cycle Assessment of the hull of a high-speed craft

A comparative Life Cycle Assessment is performed for different structural material concepts on a 24-m-long high-speed patrol craft. The study is comparative and determines the differences in and sensitivities to environmental impact, especially in relation to the total impact of fuel burn for the different material concepts. The material concepts are aluminium and various composite combinations consisting of glass fibre and carbon fibre with vinyl ester resin both as single skins and as sandwich with a Divinycell foam core. Commercially available standard Life Cycle Assessment software is used for the Life Cycle Assessment calculations. The study shows that regardless of hull material concept, the environmental impact is dominated by the operational phase due to relatively large fuel consumption. In the operational phase, the lightest carbon-fibre concept is shown to have least environmental impact. Considering the manufacturing phase exclusively for the different hull concepts, it is concluded that the manufacturing of the aluminium hull has a somewhat larger environment impact for the majority of Life Cycle Assessment impact categories in comparison to the different composite hulls. The significant impact on the marine and the fresh water aquatic ecotoxicity originates from the aluminium raw material excavation and manufacturing processes. It is shown that the lightest hull, the carbon-fibre sandwich concept, with a 50% structural weight reduction compared to the aluminium design, can be utilized to reduce the fuel consumption by 20% (775 ton of diesel) over the lifetime with significant impact on the dominating environmental aspects considered herein, abiotic depletion, global warming and acidification.

Integrating Life Cycle Assessment with Green Building and Product Rating Systems: North American Perspective

The development of green building rating systems (GBRS) and sustainability metrics for buildings, including building products, is reviewed from a North American perspective. The Leadership in Energy and Environmental Design (LEED) system and the Living Building Challenge (LBC) are highlighted as primary examples of different levels of GBRS. Life cycle assessment (LCA) is introduced as a preferred method of quantifying sustainability, and its integration into current GBRS is examined a prominent building example. Two example applications of LCA to building products associated with GBRS – carpet and roof membranes – are provided. In the first example, conventional carpet was compared with carpet meeting the standards of the LBC's materials exclusion criteria (Red List, via the Declare product labeling system). In the second example, LCA was applied to both the manufacture and use phases of roof membrane alternatives for a building retrofit project, one of which would have aided in achieving LEED certification. The Declare-listed products did not perform better in every LCA impact category, and the GBRS-preferred roof system performed more poorly in all LCA impact categories, while suggesting the need for additional LCA categories. Both examples help to illustrate the complexity and tradeoffs encountered while integrating the quantitative perspective of LCA and the qualitative perspective of GBRS.

Cradle-to-gate life cycle assessment of precipitated calcium carbonate production from steel converter slag

Precipitated calcium carbonate (PCC), a filler and pigment material, is typically produced by calcining limestone at high temperature processes and by re-carbonating the formed calcium oxide in an aqueous solution. This process causes significant carbon dioxide emissions, while it enables particle size and quality control during processing. An alternative PCC production method named Slag2PCC, where steel converter slag is used as a calcium source instead of limestone, has been recently developed at Finnish universities. When these methods are compared by means of a cradle-to-gate life cycle assessment (LCA), it is confirmed that the Slag2PCC approach has negative CO2 emissions, i.e. the process captures more CO2 than what is generated. Also, regarding other studied LCA impact categories, human health, ecosystem quality and resources, the alternative method is more environmentally benign. However, if excessive after-treatment processes are required for e.g. purifying the produced PCC, the new approach will pollute more than the traditional PCC manufacturing.

Life cycle assessment analysis of active and passive acid mine drainage treatment technologies

Acid mine drainage (AMD), resulting from open-cast coal mining, is currently one of the largest environmental challenges facing the mining industry. In this study, a life cycle assessment (LCA) was conducted to evaluate the environmental impacts associated with the construction, operation and maintenance of different AMD treatment options typically employed. LCA is a well-reported tool but is not documented for AMD treatment systems despite their ubiquitous implementation worldwide. This study conducted detailed LCA analysis for various passive and active AMD treatment approaches implemented or considered at a major coal mine in New Zealand using a comparative functional unit of kg acidity removed per day for each treatment option. Eight treatment scenarios were assessed including active limestone and hydrated lime treatments, and compared to passive treatments using limestone and waste materials such as mussel shells. Both midpoint and endpoint LCA impact categories were assessed. Generally, the active treatment scenarios demonstrated greater LCA impacts compared to an equivalent level of treatment for the passive treatment approaches. Lime slaking had the greatest LCA impacts, while passive treatment approaches incurred consistently less impacts except for one passive treatment with a purchased energy scenario. A 50% reduction in transportation distances resulted in the lowest LCA impacts for all scenarios. This study highlights the importance of evaluating the environmental and social impacts of AMD treatment for the mining industry.

Life cycle assessment of a food waste composting system: environmental impact hotspots

Abstract A life cycle assessment (LCA) approach was used to identify the processes and stages in organic waste composting that have the largest environmental impacts. The LCA included impacts associated with the collection of feedstock, production and distribution of compost, and its use as a replacement for peat for soil conditioning. The use phase of the compost product has not been included in previous LCA studies in the United States. Nine LCA impact categories were analyzed (global warming potential, ozone depletion, smog, acidification, eutrophication, carcinogens, non-carcinogens, respiratory effects, and ecotoxicity) using TRACI 2 methodology. The functional unit was defined as the collection, processing, transportation, and application of one tonne of compost that meets USEPA composting standards. The compost was produced at the Organics Material Processing and Education Center (OMPEC) at The Pennsylvania State University. The data used in the assessment was collected from seven composting windrows over thirteen consecutive months (December 2010–January 2012). Given the wide range of decomposition emission factors reported in the literature for methane (CH 4 ), nitrous oxide (N 2 O) and ammonia (NH 3 ), three emission scenarios were calculated: average, minimum, and maximum emission scenarios. Carbon dioxide (CO 2 ) emissions from the compost were considered biogenic and not included in the assessment. For all scenarios, compost processing was the stage with the largest environmental impact, with decomposition emissions contributing the most to global warming potential, acidification and eutrophication impact categories under the average and maximum emissions scenarios. To account for the avoided environmental impacts of peat mining and transport, these values were subtracted from the composting life cycle. The avoided impacts from peat replacement were higher than the impacts from composting for all categories, illustrating that using compost instead of peat results in net environmental gains. This study highlights the importance of minimizing life cycle impacts associated with CH 4 , N 2 O and NH 3 emissions during the decomposition process and the need for more consensus in the literature on emission values from composting processing.

What Scientific Issues in Life Cycle Assessment Applied to Waste and Biomass Valorization? Editorial

Whereas life cycle assessment (LCA) is more and more used for assessing the environmental load of waste management systems and of biomass production and valorization systems, various scientific issues are still to be dealt with. The purpose of this paper is to enlighten these scientific issues and to describe the current attempt to overcome them. The method used has been to go through the steps of the LCA standardized framework (ISO 14040) and to outline at each step the points that could be improved and still deserve research efforts. The various identified issues are: in step 1 (goal and scope), the choice of attributional/consequential modelling, the difficult choice of the functional unit due to the highly multi-functional nature of such systems, the allocation choices and the need for spatial differentiation; in step 2 (inventory), the thorny issue of modelling such complex systems and properly estimating field emissions; in step 3 (impact assessment), the lack of appropriate impacts (such as odours) in current LCA impact categories; in step 4 (interpretation and use), research efforts are needed to understand and facilitate the way actors take over and use LCA multi-criteria results. A transversal issue, i.e. uncertainty characterization and reduction, is also analyzed. These various scientific bottlenecks are currently under study; some are handled by this “Waste and Biomass Valorization” special topic, which includes a selection of papers presented in 2011 at the Ecotech&Tools conference (Montpellier, France).

LCA of cropping systems with different external input levels for energetic purposes

Abstract Biofuels could become increasingly important for agriculture; however there is growing concern regarding the possible environmental drawbacks due to the risks of increased inputs during crop cultivation. These risks need to be evaluated in order to assess the best management practices. In this study, a life cycle assessment (LCA) was carried out: (i) to evaluate the environmental impacts of three cropping systems characterized by different external input levels (low S1, medium S2 and high S3) applied to sunflower and maize, both in rotation with wheat, in a Mediterranean region; (ii) to estimate the environmental benefits of the optimization of cropping systems for energy management. Output–input ratio, net energy balance, global warming potential (GWP), eutrophication potential (EP) and acidification potential (AP) were used as LCA impact categories. Data from cropping systems (external input and crop yields) were collected from a long-term experiment carried out in the coastal plain of Tuscany; data regarding fertilizers, machinery and pesticide production were taken from literature. The results obtained showed S1 with the highest output–input ratios and the lowest impact for the selected impact categories. The other cropping systems S2 and S3 showed limited differences between them for all the impact categories evaluated. Fertilizer use and application, irrigation and machinery use caused most of the environmental impacts and energy consumption. The allocation procedure, showing residues as co-products, had a strong influence on the overall efficiency of agricultural systems.

Extended Life Cycle Assessment of Southern Pink Shrimp Products Originating in Senegalese Artisanal and Industrial Fisheries for Export to Europe

Southern pink shrimp (Penaeus notialis) are an important Senegalese export commodity. Artisanal fisheries in rivers produce 60%. Forty percent are landed in trawl fisheries at sea. The shrimp from both fisheries result in a frozen, consumer-packed product that is exported to Europe. We applied attributional life cycle assessment (LCA) to compare the environmental impact of the two supply chains and identify improvement options. In addition to standard LCA impact categories, biological impacts of each fishery were quantified with regard to landed by-catch, discard, seafloor impact, and size of target catch. Results for typical LCA categories include that artisanal fisheries have much lower inputs and emissions in the fishing phase than does the industrial fishery. For the product from artisanal fisheries, the main part of the impact in the standard LCA categories occurs during processing on land, mainly due to the use of heavy fuel oil and refrigerants with high global warming and ozone depletion potentials. From a biological point of view, each fishery has advantages and drawbacks, and a number of improvement options were identified. If developing countries can ensure biological sustainability of their fisheries and design the chain on land in a resource-efficient way, long distance to markets is not an obstacle to sustainable trading of seafood products originating in artisanal fisheries.

Environmental assessment of the Atlantic mackerel (Scomber scombrus) season in the Basque Country. Increasing the timeline delimitation in fishery LCA studies

The purpose of this study was to evaluate the environmental impacts linked to fish extraction on a temporal basis, in order to analyze the effect that stock abundance variations may have on reporting environmental burdens. Inventory data for the North-East Atlantic Mackerel (NEAM) fishing season were collected over an 8-year period and used to carry out a life cycle assessment (LCA). The selected fishery corresponds to the Basque coastal purse seining fleet. The functional unit (FU) was set as 1 t of landed round fish in a Basque port during the NEAM fishing season for each of the selected years. The selected data for the life cycle inventory were gathered from personal communication from ship owners and from a fish first sale register in the Basque Country. A series of fishery-specific impact categories and indicators were included in the evaluation together with conventional impact categories. Conventional LCA impact categories showed that the environmental impact is dominated by the energy use in the fishery, despite of the low fuel effort identified with respect to other purse-seining fisheries. Nevertheless, strong differences were identified between annual environmental impacts, attributed mainly to remarkable variations in NEAM stock abundance from 1 year to another, whereas the fishing effort remained relatively stable throughout the assessed years. Fishery-specific categories, such as the discard rate or seafloor impact showed reduced impacts of this fishery respect to other small pelagic fish fisheries. Finally, the fishery in balance (FiB) index identified the evolution of NEAM stock abundance for this particular fishery. To our knowledge, this is the first fishery LCA study in which there is sufficient inventory data in order to conduct the methodology throughout a wide period of time. The outstanding variance in environmental impacts from one season to another evidences the need to expand fishery LCAs in time, in order to attain a more integrated perspective of the environmental performance of a certain fishery or species. The extension of LCA inventories in the timeline may be an important improvement for activities that rely entirely on the extraction of organisms from wild ecosystems. For instance, future research will have to determine the importance of increasing the timeline in fishery LCAs for species that do not show large stock abundance variations through time, unlike NEAM.

Life cycle modelling of environmental impacts of application of processed organic municipal solid waste on agricultural land (Easewaste)

A model capable of quantifying the potential environmental impacts of agricultural application of composted or anaerobically digested source-separated organic municipal solid waste (MSW) is presented. In addition to the direct impacts, the model accounts for savings by avoiding the production and use of commercial fertilizers. The model is part of a larger model, Environmental Assessment of Solid Waste Systems and Technology (EASEWASTE), developed as a decision-support model, focusing on assessment of alternative waste management options. The environmental impacts of the land application of processed organic waste are quantified by emission coefficients referring to the composition of the processed waste and related to specific crop rotation as well as soil type. The model contains several default parameters based on literature data, field experiments and modelling by the agro-ecosystem model, Daisy. All data can be modified by the user allowing application of the model to other situations. A case study including four scenarios was performed to illustrate the use of the model. One tonne of nitrogen in composted and anaerobically digested MSW was applied as fertilizer to loamy and sandy soil at a plant farm in western Denmark. Application of the processed organic waste mainly affected the environmental impact categories global warming (0.4-0.7 PE), acidification (-0.06 (saving)-1.6 PE), nutrient enrichment (-1.0 (saving)-3.1 PE), and toxicity. The main contributors to these categories were nitrous oxide formation (global warming), ammonia volatilization (acidification and nutrient enrichment), nitrate losses (nutrient enrichment and groundwater contamination), and heavy metal input to soil (toxicity potentials). The local agricultural conditions as well as the composition of the processed MSW showed large influence on the environmental impacts. A range of benefits, mainly related to improved soil quality from long-term application of the processed organic waste, could not be generally quantified with respect to the chosen life cycle assessment impact categories and were therefore not included in the model. These effects should be considered in conjunction with the results of the life cycle assessment.

Is it feasible to address indoor climate issues in LCA?

Life cycle assessment (LCA) is frequently used as a tool for environmental assessment of buildings and building products. Generally, the main focus of LCA is the impact on the regional and global external environment. However, there are important environmental problems related to buildings that arise locally in connection with the indoor environment, such as effects on human health. The approaches of LCA, measurements of emissions from building materials, and indoor climate assessment were studied to see how they relate to each other from a methodological point of view, using volatile organic compound (VOC) emissions as an example. The possibility of including indoor climate issues as an impact category in LCA of building products was investigated. Only very limited aspects of the indoor climate could be addressed in LCA; thus, indoor climate issues are preferably dealt with separately.

Ecological assessment of the environmental impacts of the kerosene burning in jet turbines and its improvement assessment

The burning of kerosene in jet turbines is investigated for two reference flights with a Boeing 747-400 and an Airbus A320-200, representing the typical Lufthansa planes for long and middle distance. The ecological evaluation is performed by Life Cycle Assessment (LCA). Formation of condensation trails, which is a specific environmental impact caused by air traffic, has to be considered in addition to established LCA impact categories. Based on the ecological assessment, an improvement assessment is performed. Environmental performance of diesel fuel during the combustion in car engines is analysed based on available publications. The relevant parameters for the environmental impact of the combustion of diesel (aromatics content, reduction of sulphur content, the reduction of the density and raising of the cetane number) are discussed with regard to improvements of the exhaust qualities of kerosene. A reduction of the aromatics content promises to improve the emission of soot which should be further investigated.

Life cycle assessment and multiobjective optimisation

Life cycle assessment (LCA) is a method to identify and quantify the environmental performance of a process or a product from “cradle to grave”. Its main potential in environmental decision-making lies in providing a quantitative basis for assessing potential improvements in environmental performance of a system throughout the life cycle. This paper introduces the use of multiobjective system optimisation in LCA as a tool for identifying and evaluating the best possible options for environmental management of the product system. A life cycle of a system is optimised on a number of environmental objective functions, defined in terms of the usual LCA burden or impact categories, and a range of environmental optima is found on the Pareto or non-inferior surface. As a result, possibilities for improving the environmental performance of the system are identified. Since system improvements cannot be carried out on the basis of environmental LCA only, it is also shown in this paper that the compromise between environmental and economic performance can be found on the non-inferior surface. The value of multiobjective optimisation in system analysis lies in providing a set of alternative options for system improvements rather than a single prescriptive solution, thus enabling the choice of the Best Practicable Environmental Option (BPEO) and Best Available Technique Not Entailing Excessive Cost (BATNEEC). This approach is illustrated by application to a real case study of a system producing five borate products.