Critical review of guidelines against a systematic framework with regard to consistency on allocation procedures for recycling in LCA

Purpose

Multifunctionality in LCA can be solved by several allocation procedures. Various official guidelines give divergent recommendations in which allocation procedure to apply, and up to now, no consensus has been reached. We aim to identify the obstacles to a consistent allocation approach that can be applied to all product categories and is supported by a broad range of stakeholders.

Methods

Based on a systematic framework for consistent allocation, developed by Schrijvers et al. (Int J Life Cycle Assess, 2016), we identify five review criteria that indicate the degree of consistency in the proposed allocation procedure of official guidelines. Several relevant guidelines, i.e. ISO 14044, ISO/TR 14049, ISO/TS 14067, the ILCD Handbook, BP X30-323-0, PAS 2050, the Greenhouse Gas Protocol, EN15804, PEF Guide and guidance documents for EPDs and PCRs, are reviewed according to these criteria.

Results and discussion

None of the investigated guidelines fully follows the systematic framework for allocation. Often, different approaches are recommended for co-products and recycled materials, although the boundary between these flows is not always clear. Many guidelines do not recognize the existence of different LCA goals; therefore, elements of attributional and consequential LCAs are often mixed. The market situation of the recycled material is not always taken into account, e.g. in the mandatory 50/50 method of the PEF Guide. The ILCD Handbook and the General Programme Instructions for the International EPD® System provide most consistent guidance. We argue that consistency does not require a one-formula-fits-all method, as this would favour some product categories and only responds to a certain LCA goal.

Conclusions and perspectives

A critical review of guidelines against a systematic framework for allocation of co-products and recycled materials shows that few guidelines propose a consistent allocation approach. The main obstacles for consistency are the different approaches for co-production and (different types of open-loop) recycling and disregarding of different LCA goals and recycled material markets. We recommend to include material specific guidance in Product Category Rules on the determination of market prices, quality determining factors and relevant material properties for different applications.

     

Towards a general framework for including noise impacts in LCA

Purpose  

Several damages have been associated with the exposure of human beings to noise. These include auditory effects, i.e., hearing impairment, but also non-auditory physiological ones such as hypertension and ischemic heart disease, or psychological ones such as annoyance, depression, sleep disturbance, limited performance of cognitive tasks or inadequate cognitive development. Noise can also interfere with intended activities, both in daytime and nighttime. ISO 14'040 also indicated the necessity of introducing noise, together with other less developed impact categories, in a complete LCA study, possibly changing the results of many LCA studies already available. The attempts available in the literature focused on the integration of transportation noise in LCA. Although being considered the most frequent source of intrusive impact, transportation noise is not the only type of noise that can have a malign impact on public health. Several other sources of noise such as industrial or occupational need to be taken into account to have a complete consideration of noise into LCA. Major life cycle inventories (LCI) typically do not contain data on noise emissions yet and characterisation factors are not yet clearly defined. The aim of the present paper is to briefly review what is already available in the field and propose a new framework for the consideration of human health impacts of any type of noise that could be of interest in the LCA practice, providing indications for the introduction of noise in LCI and analysing what data is already available and, in the form of a research agenda, what other resources would be needed to reach a complete coverage of the problem.     

Data representativeness in LCA: A framework for the systematic assessment of data quality relative to technology characteristics

A shortcoming in current data quality assessment schemes is that the data quality information is not used systematically to identify the critical data in a life cycle inventory (LCI) model. In addition, existing criteria employed to evaluate representativeness lack relevance to the specific context of a study. A novel framework is proposed herein for the evaluation of the representativeness of LCI data, including an analysis of the importance of the data and a modification of quality criteria based on unit process characteristics. Temporal characteristics are analyzed by identifying the technology shift, because data generated before this time are considered outdated. Geographical and technological characteristics are analyzed by defining a “related area” and a “related technology,” which is done by identifying a number of relevant geographical and technical factors, and then comparing the collected data with these factors. The framework was illustrated in a case study on household waste incineration in Denmark. The results demonstrated the applicability of the method in practice, and they provided data quality criteria unique to waste incineration unit processes, for example, different time intervals to evaluate temporal representativeness. However, the proposed method is time demanding, and thus sector‐level characteristic analyses are feasible instead of the user having to do the analyses.     

Proposal of a method for allocation in building-related environmental LCA based on economic parameters

Application and development of the LCA methodology to the context of the building sector makes several building specific considerations necessary, as some key characteristics of products in the building sector differ considerably from those of other industrial sectors. The largest difference is that the service life of a building can stretch over centuries, rather than decades or years as seen for consumer products. The result of the long service life is that it is difficult to obtain accurate data and to make relevant assumptions about future conditions regarding, for example, recycling. These problems have implications on the issue of allocation in the building sector, in the way that several allocation procedures ascribe environmental loads to users of recycled or reused products and materials in the future which are unknown today. The long service life for buildings, building materials and building components, is associated with the introduced concept of a virtual parallel time perspective proposed here, which basically substitutes historical and future processes and values with current data. Further, the production and refining of raw material as a parallel to upgrading of recycled material, normally contains several intermediate products. A suggestion is given for how to determine the comparability of intermediate materials. The suggested method for allocation presented is based on three basic assumptions: (1) If environmental loads are to be allocated to a succeeding product life cycle, the studied actual life cycle has to take responsibility for upgrading of the residual material into secondary resources. (2) Material characteristics and design of products are important factors to estimate the recyclable amount of the material. Therefore, a design factor is suggested using information for inherent material properties combined with information of the product context at the building level. (3) The quality reduction between the materials in two following product life cycles is indicated as the ratio between the market value for the material in the products. The presented method can be a good alternative for handling the problem of open-loop recycling allocation in the context of the building sector if a consensus for the use of the fictive parallel time perspective and the use of the design factor can be established. This as the use of the time perspective and design factor is crucial to be able to deal with the problem of long service lives for buildings and building materials and the specific characteristics of the same building materials and components built into different building contexts.     

A framework for environmental decision support in cities incorporating organizational LCA

The International Journal of Life Cycle Assessment - Cities contribute to and are affected by several environmental pressures within and beyond city boundaries. Urban decision makers struggle to...     

Environmental impact evaluation of co-products: decision-aid tool for allocation in LCA

The International Journal of Life Cycle Assessment - As sustainability has become an important asset for production systems, it is important to conduct life cycle assessment (LCA) studies. When...     

Developing a regional recovery framework

A biological attack would present an unprecedented challenge for local, state, and federal agencies, the military, the private sector, and individuals on many fronts, ranging from vaccination and treatment to prioritization of cleanup actions to waste disposal. To prepare for recovery from this type of incident, the Seattle Urban Area Security Initiative (UASI) partners collaborated with military and federal agencies to develop a regional recovery framework. The goal was to identify key information that will assist policymakers and emergency managers in shortening the timeline for recovery and minimizing the economic and public health impacts of a catastrophic anthrax attack. Based on discussions in workshops, tabletop exercises, and interviews with local, state, federal, military, and private sector entities responsible for recovery, the authors identified goals, assumptions, and concepts of operation for various areas to address critical issues the region will face as recovery progresses. Although the framework is specific to a catastrophic, wide-area biological attack using anthrax, it was designed to be flexible and scalable so it could also serve as the recovery framework for an all-hazards approach in other regions and jurisdictions. Benefits from this process include enhanced coordination and collaboration across agencies, a more thorough understanding of the anthrax threat, an opportunity to proactively consider long-term recovery, and a better understanding of the specific policy questions requiring resolution.     

A framework for actualising normalisation data in LCA: Experiences in the Netherlands

In LCA, normalisation is applied to quantify the relative size of the impact scores. Several sets of normalisation data exist in the Netherlands, which all have a certain degree of unreliability. The purpose of this study is to actualise Dutch normalisation data and to make a framework for deriving these data. In this study normalisation data are calculated for three different levels in order to give the LCA practitioner a more extended basis for preparing the interpretation process. The first level of normalisation contains all impacts relating to activities that take place within the Dutch territory. The second level is based on the Dutch final consumption, which means that import and export are taken into account. The third level is an attempt to estimate impacts in Europe based on European data if possible, and otherwise based on extrapolation from the Dutch situation.     

Adapting the LCA framework to environmental assessment in land planning

Purpose

Since the implementation of the European directive (EC/2001/42) on strategic environmental assessment, an ex ante evaluation has become mandatory for plans and programs. This requirement could have significant consequences for the environment. Local authorities, who are in charge of land planning issues, must therefore conduct such assessments. However, they are faced with lack of uniform methodology. The aim of this paper is thus to propose a methodological framework for the required environmental assessment stages in land planning.

Methods

Life cycle assessment (LCA) has been identified as a promising tool to perform environmental assessment at a meso-level (i.e., territories). Yet, the standardized LCA framework has never been used for assessing the environmental impacts of a territory as such, which can be explained by the complexity that its application would involve. Four major methodological bottlenecks have been identified in this paper, i.e., (1) functional unit definition, (2) boundary selection, (3) data collecting, and (4) the refinement of the life cycle impact assessment phase in order to provide useful indicators for land planning. For each of these challenges, recommendations have been made to adapt the analytical framework of LCA.

Results and discussion

A revised framework is proposed to perform LCA of a territory. One of the major adaptations needed concerns the goal and scope definition phase. Henceforth, the association of a territory and the studied land planning scenario, defined by its geographical boundaries and its interactions with other territories, will be designated as the reference flow in LCA. Consequently, two kinds of indicators will be determined using this approach, i.e., (1) a vector of environmental impacts generated (conventional LCA) and (2) a vector of land use functions provided by the territory for different stakeholders (e.g., provision of work, recreation, culture, etc.). This revised framework has been applied to a theoretical case study in order to highlight its utility in land planning.

Conclusions

This work is a first step in the adaptation of the LCA framework to environmental assessment in land planning. We believe that this revised framework has the potential to provide relevant information in decision-making processes. Nonetheless, further work is still needed to broaden and deepen this approach (i.e., normalization of impacts and functions, coupled application with GIS, uncertainties, etc.).     

Cooperating in the face of uncertainty: a consistent framework for understanding the evolution of cooperation

The evolution of cooperative behaviour, whereby individuals enhance the fitness of others at an apparent cost to themselves, represents one of the greatest paradoxes of evolution. Individuals that engage in such cooperative behaviour can, however, be favoured by natural selection if cooperative actions confer higher fitness than alternative actions. To understand the evolution of cooperative behaviour, the direct and indirect genetic benefits that individuals accrue in the present and future must be summed - this can be accomplished without any reference to the colorful vocabulary typically associated with studies of cooperation. When benefits are accrued indirectly through relatives or directly in the future individuals must be able to assess and enhance their probability of accruing those benefits and behave accordingly. We suggest that, in the same way that studies of kin recognition systems improved our understanding of how individuals assess and enhance their probability of accruing indirect benefits, studies of various forms of inheritance and reciprocation recognition systems will improve our understanding of how individuals assess and enhance their probability of accruing future benefits. Recognizing the parallel between studies of indirect fitness and future fitness, at multiple levels of analysis, will move us toward a simpler and more consistent framework for understanding the evolution of cooperative behaviour.     

A decision-analytic framework for impact assessment part I: LCA and decision analysis

Life-cycle assessments (LCAs) are conducted to satisfy the aspiration of decision makers to consider the environment in their decision making. This paper reviews decision analysis and discusses how it can be used to structure the assessment and to integrate characterization and valuation. The decision analytic concepts of objectives (goals) and attributes (indicators of the degree to which an objective is achieved) are used to describe steps of the assessment of the entire impact chain. Decision analysis distinguishes among different types of objectives and attributes; it describes how these relate to each other. Impact indicators such as the Human Toxicity Potential are constructed attributes. A means-ends objectives network can show how the different constructed attributes relate to the objective of protecting the environment. As LCA takes disparate environmental impacts into account, it needs to assess their relative importance. Trade-off methods in decision analysis are grouped into utility theory and multicriteria decision aids; they have different advantages and disadvantages, but are all more sophisticated than simple weighting. The performance of the different trade-off methods has not yet been tested in an LCA context. In the second part of the paper, we present criteria for the development of characterization methods.     

Implementing vertex dynamics models of cell populations in biology within a consistent computational framework

The dynamic behaviour of epithelial cell sheets plays a central role during development, growth, disease and wound healing. These processes occur as a result of cell adhesion, migration, division, differentiation and death, and involve multiple processes acting at the cellular and molecular level. Computational models offer a useful means by which to investigate and test hypotheses about these processes, and have played a key role in the study of cell–cell interactions. However, the necessarily complex nature of such models means that it is difficult to make accurate comparison between different models, since it is often impossible to distinguish between differences in behaviour that are due to the underlying model assumptions, and those due to differences in the in silico implementation of the model. In this work, an approach is described for the implementation of vertex dynamics models, a discrete approach that represents each cell by a polygon (or polyhedron) whose vertices may move in response to forces. The implementation is undertaken in a consistent manner within a single open source computational framework, Chaste, which comprises fully tested, industrial-grade software that has been developed using an agile approach. This framework allows one to easily change assumptions regarding force generation and cell rearrangement processes within these models. The versatility and generality of this framework is illustrated using a number of biological examples. In each case we provide full details of all technical aspects of our model implementations, and in some cases provide extensions to make the models more generally applicable.     

A framework for including enhanced exposure to naturally occurring radioactive materials (NORM) in LCA

Purpose

Despite advances in the development of impact categories for ionising radiation, the focus on artificial radionuclides produced in the nuclear fuel cycle means that the potential impacts resulting from increased exposure to naturally occurring radioactive materials (NORM) are still only covered to a limited degree in life cycle assessment (LCA). Here, we present a potential framework for the inclusion of the exposure routes and impact pathways particular to NORM in LCA.

Methods

We assess the potential magnitude of enhanced NORM exposure, particularly in light of the potential use of NORM residues in building materials, and set out the potential exposure routes that may exist. We then assess the current state of the art, in terms of available fate, exposure and damage models, both within and outside of the LCA sphere. Finally, these exposure routes and modelling techniques are combined in order to lay out a potential framework for NORM assessment in LCA, both in terms of impact on humans and ecosystems.

Results and discussion

Increased exposure to NORM radionuclides can result either from their release to the environment or their proximity to humans as they reside in stockpiles, landfills or products. The exposure route via products is considered to be increasingly significant in light of current attempts to incorporate technologically enhanced NORMs (TENORM) including bauxite residue into building materials, by groups such as the ETN-MSCA REDMUD project. Impact assessment models for NORM exposure are therefore required to avoid potential burden shifting in the assessment of such TENORM products. Models describing the fate of environmental releases, the exhalation of radon from building products and the shielding effects on landfills/stockpiles are required to assess potential exposure. Subsequently, models relating exposure to radiation sources and the effective internal and external dose received by receptors are required. Finally, an assessment of the damage caused to the receptors is desirable.

Conclusions

A sufficient suite of currently existing and internationally recognised models exist that can, with varying degrees of modification, form the building blocks of a comprehensive NORM characterisation method for LCA. The challenge ahead lies in consolidating these models, from disparate fields, into a coherent and generally applicable method for the assessment of enhanced NORM exposure in LCA.

     

The kinetics of bovine growth hormone folding are consistent with a framework model

The framework model of protein folding requires the hydrogen-bonded secondary structure to be formed early in folding (i.e. the formation of secondary structure precedes the tertiary structure) (Kim, P. S., and Baldwin, R. L. (1982) Annu. Rev. Biochem. 51, 459-489). To test the framework model directly the kinetics of bovine growth hormone (bGH) folding were compared utilizing two methods of detection, one that measures the secondary structure (far ultraviolet circular dichroism) and another that measures the tertiary structure (near ultraviolet absorbance). The results demonstrate that, under identical folding conditions, the kinetics observed by far ultraviolet circular dichroism are faster than those observed by ultraviolet absorption. The faster kinetics observed by circular dichroism indicate the existence of a helix-containing intermediate which is consistent with the framework model. The effect of protein concentration and denaturant concentration on the kinetics of refolding were studied. The rate of refolding measured by absorbance and circular dichroism was dependent on protein concentration. The protein concentration dependence on refolding is due to the transient formation of an associated intermediate. The concentration dependence of folding is taken as evidence that folding is a sequential process with partially folded monomers responsible for the observed association effect. At dilute protein concentrations the refolding can be studied independent of the association phenomena. The growth hormones utilized in this study were derived from Escherichia coli through recombinant DNA technology and from bovine pituitaries. The pituitary-derived bGH has been shown to be heterogeneous at the NH2 terminus (Lorenson, M. F., and Ellis, S. (1975) Endocrinology 96, 833-838), whereas the recombinant DNA-derived bGH contains a single NH2 terminus. No differences in the folding kinetics between the recombinant DNA and pituitary derived-bGH were observed. It is concluded that the heterogeneity of the NH2 terminus of growth hormone obtained from bovine pituitaries does not affect the observed in vitro folding kinetics.     

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

Purpose

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

Methods

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

Results and discussion

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

Conclusions

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