Characterization Factors Research Articles

Regionalized life cycle impact assessment of air pollution on the global scale: Damage to human health and vegetation

We developed regionalized characterization factors (CFs) for human health damage from particulate matter (PM2.5) and ozone, and for damage to vegetation from ozone, at the global scale. These factors can be used in the impact assessment phase of an environmental life cycle assessment. CFs express the overall damage of a certain pollutant per unit of emission of a precursor, i.e. primary PM2.5, nitrogen oxides (NOx), ammonia (NH3), sulfur dioxide (SO2) and non-methane volatile organic compounds (NMVOCs). The global chemical transport model TM5 was used to calculate intake fractions of PM2.5 and ozone for 56 world regions covering the whole globe. Furthermore, region-specific effect and damage factors were derived, using mortality rates, background concentrations and years of life lost. The emission-weighted world average CF for primary PM2.5 emissions is 629 yr kton−1, varying up to 3 orders of magnitude over the regions. Larger CFs were obtained for emissions in central Asia and Europe, and smaller factors in Australia and South America. The world average CFs for PM2.5 from secondary aerosols, i.e. NOx, NH3, and SO2, is 67.2 to 183.4 yr kton−1. We found that the CFs for ozone human health damage are 2–4 orders of magnitude lower compared to the CFs for damage due to primary PM2.5 and PM2.5 precursor emissions. Human health damage due to the priority air pollutants considered in this study was 1.7·10−2 yr capita−1 worldwide in year 2010, with primary PM2.5 emissions as the main contributor (62%). The emission-weighted world average CF for ecosystem damage due to ozone was 2.5 km2 yr kton−1 for NMVOCs and 8.7 m2 yr kg−1 for NOx emissions, varying 2–3 orders of magnitude over the regions. Ecosystem damage due to the priority air pollutants considered in this study was 1.6·10−4 km2 capita−1 worldwide in 2010, with NOx as the main contributor (72%). The spatial range in CFs stresses the importance of including spatial variation in life cycle impact assessment of priority air pollutants.

A spatially explicit life cycle assessment midpoint indicator for soil quality in the European Union using soil organic carbon

Improving land use assessment in life cycle assessment (LCA) is a priority. Recently, soil organic carbon (SOC) depletion has been proposed as a transformation and occupation midpoint indicator to estimate impacts on biotic production potential (BPP). SOC depletion is recommended by the European Union in the International Reference Life Cycle Data System (ILCD) Handbook as a land use indicator. There is a consensus method to calculate SOC depletion in LCA, and ILCD proposes a set of characterization factors (CFs), but these lack geographical discrimination. Our method of calculation for midpoint CFs follows Brandao and Mila i Canals (Int J Life Cycle Assess 18:1243–1252, 2013). We operationalize the method using SOC stocks from the LUCASOIL database of field measurements in Europe. We use potential natural vegetation (PNV) as the reference situation. CFs were calculated on a cell basis for 23 countries in Europe and grouped in three spatial scales (an administrative classification, NUTS II, and two biophysical classifications, ecoregion and climate region) according to soil type and land cover following a consensus map of cover classes. To evaluate the method’s results, CFs were applied in a case study. SOC stocks of European soils were obtained according to land use and soil type classes (excluding non-European Union countries) for the three spatial scales. A database of European transformation and occupation CFs is also presented and analyzed. The aggregation of CFs at biophysical scales (ecoregion and climate region) is similar, but NUTS II aggregation of CFs is problematic. The application of the CFs in the case study revealed significant differences compared to the outcome of using CFs collected from other land use models. This paper is the first operationalization using field measurements of an updated version of the ILCD-recommended model for land use impacts in LCA. We obtained CFs for SOC depletion in Europe that can be nested within CFs suggested by ILCD since our results possess better spatial resolution but are only for European Union countries. The case study application highlighted the need for inventories to improve the spatial resolution of the life cycle processes to match the detail of LCIA models.

Characterization factors for zinc terrestrial ecotoxicity including speciation

Ignoring metal speciation in the determination of characterization factors (CFs) in life cycle assessment (LCA) could significantly alter the validity of LCA results since toxicity is directly linked to bioavailability. Zinc terrestrial ecotoxicity CFs are obtained using modified USEtox fate factors, WHAM 6.0-derived bioavailable factors, and effect factors calculated using the assessment of mean impact (AMI) method with available terrestrial ecotoxicity data. Soil archetypes created using influent soil properties on Zn speciation (soil texture, pH, cation exchange capacity, organic matter and carbonate contents) are used to group soils of the world into a more manageable spatial resolution for LCA. An aggregated global CF value is obtained using population density as a Zn emission proxy. Results are presented in a world map to facilitate use. When using soluble Zn as the bioavailable fraction, CF values vary over 1.76 orders of magnitude, indicating that a single aggregated value could reasonably be used for the world. When using true solution Zn, CFs cover 14 orders of magnitude. To represent this variability, 518 archetypes and 13 groups of archetypes were created. Aggregated global default values are 4.58 potentially affected fraction of species (PAF) m3·day kg−1 for soluble Zn and 1.45 PAF m3·day kg−1 for true solution Zn. These values are respectively 28 and 88 times lower than the Zn terrestrial CF in IMPACT 2002 (128 PAF m3·day kg−1). The CFs obtained for Zn, except for soluble Zn, are at least 2 orders of magnitude lower than current CFs. However, they must be tested in case studies to measure the impact of including Zn speciation in the CF definition of terrestrial ecotoxicity.

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

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

Accounting for land use in life cycle assessment: The value of NPP as a proxy indicator to assess land use impacts on ecosystems

Terrestrial land and its resources are finite, though, for economic and socio-cultural needs of humans, these natural resources are further exploited. It highlights the need to quantify the impact humans possibly have on the environment due to occupation and transformation of land. As a starting point of this paper (1st objective), the land use activities, which may be mainly socio-culturally or economically oriented, are identified in addition to the natural land-based processes and stocks and funds that can be altered due to land use. To quantify the possible impact anthropogenic land use can have on the natural environment, linked to a certain product or service, life cycle assessment (LCA) is a tool commonly used. During the last decades, many indicators are developed within the LCA framework in an attempt to evaluate certain environmental impacts of land use. A second objective of this study is to briefly review these indicators and to categorize them according to whether they assess a change in the asset of natural resources for production and consumption or a disturbance of certain ecosystem processes, i.e. ecosystem health. Based on these findings, two enhanced proxy indicators are proposed (3rd objective). Both indicators use net primary production (NPP) loss (potential NPP in the absence of humans minus remaining NPP after land use) as a relevant proxy to primarily assess the impact of land use on ecosystem health. As there are two approaches to account for the natural and productive value of the NPP remaining after land use, namely the Human Appropriation of NPP (HANPP) and hemeroby (or naturalness) concepts, two indicators are introduced and the advantages and limitations compared to state-of-the-art NPP-based land use indicators are discussed. Exergy-based spatially differentiated characterization factors (CFs) are calculated for several types of land use (e.g., pasture land, urban land).

A comparison of two different biodiversity assessment methods in LCA—a case study of Swedish spruce forest

Purpose Lately, there has been a growing interest in how to include biodiversity in life cycle assessment (LCA). The aim of this study was to compare two impact assessment methods, with regard to their applicability on a regional level and their feasibility in terms of data availability, through applying them to a case study. MethodsThe methods tested were those developed by de Baan et al. (2013a), based on species richness, and Lindner et al. (2014), based on ecosystem indicators. These were applied to commercially managed spruce forest in the south of Sweden. For the species-based method, characterization factors (CFs) were based on species richness of vascular plants in the region, calculated for two different stages in the production cycle, before and after felling, and using two different types of semi-natural reference situations. The key feature in the ecosystem approach was a set of indicators of prerequisites for biodiversity, based on expert knowledge, and the reference situation applied was the hypothetic maximum biodiversity quality in the region. Results and discussionThe results showed that both methods were applicable for biodiversity assessment at regional level. All methodological requirements, such as species data and expert opinion, were available. To obtain enough data for the species richness method, data on vascular plants from two administrative regions was needed. When biodiversity was assessed before felling and using the spruce reference situation, the conventional spruce forestry studied was shown to have positive impact on biodiversity. All other results showed negative impacts on biodiversity. The positive impact indicated by the species richness method was probably due to the small difference in species richness between the mature spruce forest assessed and the available spruce forest reference situation. ConclusionsThe study shows that the two methods are applicable on a regional level, although data availability was a constraint in the species richness method by de Baan et al. (2013a). The choice of reference situation, and when in the production cycle assessment was made, led to considerable differences in the characterization factors generated.

Sea use impact category in life cycle assessment: characterization factors for life support functions

The impact of human activities on marine environments is poorly addressed by the scope of life cycle impact assessment (LCIA). The aim of this study is to provide characterization factors to assess impacts of sea use such as fishing activities or seafloor destruction and transformation on the life support functions of marine ecosystems. The consensual framework of land use for ecosystem services damage potential assessment was applied, according to the recent United Nations Environment Programme-Society for Environmental Toxicology and Chemistry (UNEP-SETAC) guidelines, using the free net primary production as a quality index of life support functions. The impact of shading, biomass removal, seafloor destruction, and artificial habitat creation on the available quantity of organic biomass for the ecosystem functioning was quantified at the midpoint level with a common unit (kg of organic carbon equivalent). It included effects of human interventions on both the ecosystem production potential and the stock of biomass present within the ecosystem. Characterization factors (CF) for biomass removal vary from 0.1 kgCeq kg−1 for seaweed to 111.1 kgCeq kg−1 for tunas, bonitos, and billfishes. CF for seafloor destruction range from 0.164 kgCeq m−2 for a temperate seagrass ecosystem to 0.342 kgCeq m−2 for an intertidal tropical rocky habitat. This study provides an operational method in order to compute sea use impact assessment.

Global land use impacts on biomass production—a spatial-differentiated resource-related life cycle impact assessment method

In life cycle assessment (LCA), the impact assessment on natural resources is still in the early stages of research, and the impacts of biotic resources are usually not evaluated. The human appropriation of net primary production (HANPP) is a well-known indicator of land use impacts, but it cannot be easily implemented in LCA. The objective of this paper was to create a life cycle impact assessment (LCIA) method on land use impacts on net primary production (NPP) based on the HANPP approach. To create an operational LCIA method, the midpoint characterization factors (CF) were calculated by comparing the NPP of plants occurring under current land uses with a baseline scenario, i.e., the NPP of potential natural vegetation. For the endpoint CF, we considered the backup technology concept and included in the calculation the marginal cost for additional biomass production through algae cultivation in the ocean. Site-generic and site-specific midpoint and endpoint characterization factors (CF) were created in a global scale for 162 countries and for four types of land uses (cropland, pasture, infrastructure, and wilderness). For cropland, we also created biomass-specific CF for ten particular crops in a global scale. The LCIA method was tested in particular case studies and seemed to produce comparable results, with the possibility of coupling it with other LCIA methodologies, as recipe endpoint. The LCIA method proposed in this paper provides an assessment of the decrease of biomass availability due to land use (affecting the AoP resources), which is an impact category poorly considered in LCA. Nevertheless, the method has some future challenges, for instance to take into account site-specific backup technologies for the endpoint CF.

A contribution to the environmental impact assessment of green water flows

In recent years, numerous efforts have been made to include water-related issues in life cycle assessment (LCA) methodology. This study provides an overview of existing methods that address green water use in LCA. In this overview, we analyse the main features of existing LCA methods used to examine changes in long-term blue water availability caused by variations in green water flows, particularly with respect to inventory, the characterisation model and characterisation factors.Moreover, we propose a method of assessing impacts on terrestrial green water flows (TGWI) and addressing reductions in surface blue water production (RBWP) caused by reductions in surface runoff due to land-use production systems. Both TGWI and RBWP are analysed, taking into account the green water use/atmosphere and green water use/soil interfaces.In this proposed method, the life cycle inventory (LCI) phase considers the net green water flow that leaves the land-use production system, allowing the study of two alternative reference land uses: 1) quasi-natural forest and 2) grasslands/shrublands. In the life cycle impact assessment (LCIA) phase, regional- and species-specific characterisation factors (CFs) for the amount of green water evaporated or transpired are also proposed.To illustrate the applicability of the proposed method, we employed a case study on Eucalyptus globulus stands (first rotation), located in Portugal. The results show that different impacts on terrestrial green water flows and on surface blue water production are obtained depending on the alternative reference land use. Moreover, the case study shows that the method developed can be a useful tool assisting in improved national E. globulus forest planning.

Extending life cycle assessment normalization factors and use of machine learning – A Slovenian case study

Within a life cycle assessment (LCA), normalization is an essential part for interpretation. In Europe, only the European Union normalization factors (EU NFs), with 2000 as the reference year, are available for LCA practitioners, although they work on a regional level. The hypothesis of this research was based on the assumption that some regional NFs deviate from the EU NFs due to unique regional profiles, or because of previously omitted or generalized human impact. In this particular case study set in Slovenia has been tested. By working on the ReCiPe 1.08 life cycle impact assessment methodology, 18 impact categories were investigated, and an additional 3 were added: electromagnetic radiation, light pollution and electric use. To meet practitioners’ needs, the most up-to-date inventory data was used with the reference years of 2007–2012. Out of 440 environmental interventions that were investigated, 139 had no characterization factors (CFs), 97 were estimated using machine learning and 42 had to be omitted. The final result confirmed our hypothesis. Twenty NFs were compared with the EU NFs, and the results have shown that on average, the NFs differ by a factor of 9.76 (median=1.65). The reasons for the high deviation are due to natural land transformation, and ionising radiation, toxicological and ecotoxicological impact categories; where there are major data gaps in the CFs. The primary concern of the research was data availability for toxicological and ecotoxicological parameters for toxicity-related emissions, and the fact that original CFs covered only 50.25% of plant protection products used in Slovenia. Toxicological and ecotoxicological uncertainties were illustrated by comparing four different results. Future studies should be focused on the use of machine learning to provide the next generation of CFs and to go beyond the CFs’ damage-oriented assessment. Remediation should be the new endpoint category and its units should be Joules.

Consistent characterisation factors at midpoint and endpoint relevant to agricultural water scarcity arising from freshwater consumption

PurposeThe shortage of agricultural water from freshwater sources is a growing concern because of the relatively large amounts needed to sustain food production for an increasing population. In this context, an impact assessment methodology is indispensable for the identification and assessment of the potential consequences of freshwater consumption in relation to agricultural water scarcity. This paper reports on the consistent development of midpoint and endpoint characterisation factors (CFs) for assessing these impacts.MethodsMidpoint characterisation factors focus specifically on shortages in food production resulting from agricultural water scarcity. These were calculated by incorporating country-specific compensation factors for physical availability of water resources and socio-economic capacity in relation to the irrigation water demand for agriculture. At the endpoint, to reflect the more complex impact pathways from food production losses to malnutrition damage from agricultural water scarcity, international food trade relationships and economic adaptation capacity were integrated in the modelling with measures of nutritional vulnerability for each country.Results and discussionThe inter-country variances of CFs at the midpoint revealed by this study were larger than those derived using previously developed methods, which did not integrate compensation processes by food stocks. At the endpoint level, both national and trade-induced damage through international trade were quantified and visualised. Distribution of malnutrition damage was also determined by production and trade balances for commodity groups in water-consuming countries, as well as dependency on import ratios for importer countries and economic adaptation capacity in each country. By incorporating the complex relationships between these factors, estimated malnutrition damage due to freshwater consumption at the country scale showed good correlation with total reported nutritional deficiency damage.ConclusionsThe model allows the establishment of consistent CFs at the midpoint and endpoint for agricultural water scarcity resulting from freshwater consumption. The complex relationships between food production supply and nutrition damage can be described by considering the physical and socio-economic parameters used in this study. Developed CFs contribute to a better assessment of the potential impacts associated with freshwater consumption in global supply chains and to life cycle assessment and water footprint assessments.

Spatial and temporal specific characterisation factors for water use impact assessment in Spain

Regionalised characterisation factors (CFs) for watersheds around the world are available to assess water use-related environmental impacts. The main problem with using the watershed regionalisation level arises when a single CF is generated for large watersheds in countries where water availability and demand are not uniform. Additionally, water availability and use vary over time because of the effects of climate change and changing human lifestyles. These two factors are currently not taken into account in CFs, but should be included for the sake of the accuracy of LCA results. The aim of this research was to provide water stress index CFs at the sub-watershed spatial level for three temporal scenarios (present, short-term future and mid-term future) for Spain (Southern Europe), a country with considerable variability in water availability that is especially vulnerable to climate change effects. CFs were calculated following the water stress index (WSI) definition of Pfister et al. (Environ Sci Technol 43(11):4098–4104, 2009). The WSI was calculated on a yearly basis for 117 sub-watersheds—compared to 56 regionalisation units provided in the original method—and for (i) the current situation: current water use and availability; (ii) short-term future: projections for 2015; and (iii) mid-term future: projections for 2030. The uncertainties of the CFs were calculated for each sub-watershed. Temporal trend analysis of the CFs showed a general relaxation of water stress over the short-term when compared to the current situation, followed by a new increase. Major differences were noticed in the WSIs calculated by Pfister et al. (Environ Sci Technol 43(11):4098–4104, 2009) using global data and maps and the WSIs calculated in this study using national and regional data. The WSIs under consideration of uncertainty were higher than the deterministic result for intermediate WSIs. The CFs generated are useful compared with the CFs previously available because they improve evaluation of the water use-related impacts of present and future technologies with the life cycle stages located in Spain. We encourage LCA developers to update WSIs for other countries using information at the national level that is usually freely accessible.

Characterization factors for terrestrial acidification at the global scale: A systematic analysis of spatial variability and uncertainty

Characterization factors (CFs) are used in life cycle assessment (LCA) to quantify the potential impact per unit of emission. CFs are obtained from a characterization model which assess the environmental mechanisms along the cause–effect chain linking an emission to its potential damage on a given area of protection, such as loss in ecosystem quality. Up to now, CFs for acidifying emissions did not cover the global scale and were only representative of their characterization model geographical scope. Consequently, current LCA practices implicitly assume that all emissions from a global supply chain occur within the continent referring to the characterization method geographical scope. This paper provides worldwide 2°×2.5° spatially-explicit CFs, representing the change in relative loss of terrestrial vascular plant species due to an emission change of nitrogen oxides (NOx), ammonia (NH3) and sulfur dioxide (SO2). We found that spatial variability in the CFs is much larger compared to statistical uncertainty (six orders of magnitude vs. two orders of magnitude). Spatial variability is mainly caused by the atmospheric fate factor and soil sensitivity factor, while the ecological effect factor is the dominant contributor to the statistical uncertainty. The CFs provided in our study allow the worldwide spatially explicit evaluation of life cycle impacts related to acidifying emissions. This opens the door to evaluate regional life cycle emissions of different products in a global economy.

Accounting for the occupation of the marine environment as a natural resource in life cycle assessment: An exergy based approach

The human population is rising and the availability of terrestrial land and its resources are finite and, perhaps, not sufficient to deliver enough food, energy, materials and space. Thus, it is important to (further) explore and exploit the marine environment which covers no less than 71% of the earth's surface. The marine environment is very complex but can roughty be divided into two systems: natural (e.g. wild fishing) and human-made (e.g. artificial islands). In this study, characterization factors (CF) for natural and human-made marine systems were calculated in order to be able to assess the environmental impact of occupying marine surfaces, which was not possible so far in life cycle assessment. When accounting for natural resources while occupying one of these systems, it is important to consider the primary resources that are actually deprived from nature, which differs between the natural and human-made marine systems.In natural systems, the extracted biomass was accounted for through its exergy content, which is the maximum quantity of work that the system can execute in its environment. Reference flows for marine fish, seaweeds, crustaceans and mollusks were proposed and their correlated CF was calculated. For human-made systems, the deprived land resource is, in fact, the occupied area of the marine surface. Based on potential marine net primary production data (NPP), exergy based spatial and temporal CFs for ocean areal occupation were calculated. This approach was included in the Cumulative Exergy Extraction from the Natural Environment (CEENE) method which makes it the first life cycle impact assessment (LCIA) method capable of analyzing the environmental impact (and more specific the resource footprint) of marine areal occupation. Furthermore, the methodology was applied to two case studies: comparing resource consumption of on- and offshore oil production, and fish and soybean meal production for fish feed applications.

PPCPs in wastewater – Update and calculation of characterization factors for their inclusion in LCA studies

The purpose of this paper is to provide Characterization Factors (CFs) for the toxicity related impact categories in Life Cycle Assessment (LCA) for Pharmaceuticals and Personal Care Products (PPCPs). The CFs already available were updated whereas others were implemented for the first time by means of USEtox and USES-LCA 2.0 methodologies. The list of PPCPs includes human toxicity and freshwater ecotoxicity for both models whereas terrestrial and marine ecotoxicity were assessed with USES-LCA 2.0. Moreover, all the available emission compartments were considered for the calculation. The resulting CFs were subjected to a sensitivity analysis and results determined that human toxicological and ecotoxicological effects (ED50 and avlogEC50, respectively) as well as degradation rate in water were the most sensitive parameters. The calculated CFs were used in the environmental assessment of a Completely Autotrophic Nitrogen removal Over Nitrite (CANON) pilot plant. PPCPs were found to have a major impact on freshwater ecotoxicity, accounting for 81% or 97% of the total impact with USES-LCA 2.0 and USEtox, respectively. Moreover, a more precise determination of human toxicity was obtained after updating CFs values calculated with USEtox, with contributions up to 50% of the total impact. Therefore, the provision of new and updated CFs allows a more accurate environmental assessment of processes where PPCPs are present.

Temporal differentiation of background systems in LCA: relevance of adding temporal information in LCI databases

Because the potential impacts of emissions and extractions can be sensitive to timing, the temporal aggregation of life cycle inventory (LCI) data has often been cited as a limitation in life cycle assessment (LCA). Until now, examples of temporal emission and extraction distributions were restricted to the foreground processes of product systems. The objective of this paper is to evaluate the relevance of considering the temporal distribution of the background system inventory. The paper focuses on the global warming impact category for which so-called dynamic characterization factors (CFs) were developed and uses the ecoinvent v2.2 database as both an example database to which temporal information can be added and a source of product systems to test the relevance of adding temporal information to the background system. Temporal information was added to the elementary and intermediate exchanges of 22 % of the unit processes in the database. Using the enhanced structure path analysis (ESPA) method to generate temporally differentiated LCIs in conjunction with time-dependent global warming characterization factors, potential impacts were calculated for all 4,034 product systems in the ecoinvent database. Each time, the results were calculated for (1) systems in which temporal information was only added to the first two tiers, representing studies in which only the foreground system is temporally differentiated, and (2) systems in which temporal information was also added to the background system. For 8.6 % of the database product systems, adding temporal differentiation to background unit processes affected the global warming impact scores by more than 10 %. For most of the affected product systems, considering temporal information in the background unit processes decreased the global warming impact scores. The sectors that show most sensitivity to the temporal differentiation of background unit processes are associated with wood and biofuel sectors. Even though the addition of temporal information to unit processes in LCI databases would not benefit every LCA study, the enhancement can be relevant. It allows for a more accurate global warming impact assessment, especially for LCAs in which products of biomass are present in substantial amounts. Relevance for other impact categories could be discussed in further work.

Development of a dynamic LCA approach for the freshwater ecotoxicity impact of metals and application to a case study regarding zinc fertilization

Temporal variability is a major source of uncertainty in current life cycle assessment (LCA) practice. In this paper, the recently developed dynamic LCA approach is adapted to assess freshwater ecotoxicity impacts of metals. The objective is to provide relevant information regarding the distribution and magnitude of metal impacts over time and to show whether the dynamic approach significantly influences the conclusions of an LCA. An LCA of zinc fertilization in agriculture was therefore carried out. Dynamic LCA is based on the temporal disaggregation of the inventory, which is then assessed using time-horizon-dependent characterization factors. The USEtox multimedia fate model is used to develop time-horizon-dependent characterization factors for the freshwater ecotoxicity impact of 18 metals. Mass balance equations are solved dynamically to obtain fate factors as a function of time, providing both instantaneous (impact at time t following a pulse emission) and cumulative (total time-integrated impact following a pulse emission) characterization factors (CFs). Time-horizon-dependent CFs for freshwater ecotoxicity depend on the emission compartment and the metal itself. The two variables clearly influence metal fate aspects such as the maximum mass loading reaching freshwater and the persistence time of metals into this compartment. The time needed to reach the total impact for each metal may exceed thousands of years, so the time horizon used in the analysis constitutes a determining factor. The case study reveals that the results of a classical LCA are always higher than those obtained from a dynamic LCA, especially for short time horizons. For instance, at the end of a 100-year fertilization treatment, only 25 % of the impacts obtained through traditional LCA occurred. Results show that dynamic LCA enables assessing freshwater ecotoxicity impacts of metals over time, allowing decision makers to test the sensitivity of their results to the choice of a time horizon. For the particular case study of zinc fertilization over a period of 20 years, the use of time-horizon-dependent CFs is more important in determining the dynamics of impacts than the timing of emission.

Development of Comparative Toxicity Potentials of 14 cationic metals in freshwater

Site-dependent and site-generic Comparative Toxicity Potentials (CTPs) (also known as Characterization Factors (CFs)) were calculated for 14 cationic metals (Al(III), Ba, Be, Cd, Co, Cr(III), Cs, Cu(II), Fe(II), Fe(III), Mn(II), Ni, Pb, Sr and Zn), to be applied in Life Cycle Impact Assessment. CTPs were calculated for 7 EU-archetypes, taking bioavailability and speciation pattern into account. The resulting site-dependent CTPs showed up to 2.4–6.5 orders of magnitude variation across archetypes for those metals that form stable hydroxyl compounds in slightly alkaline waters (Al(III), Be, Cr(III), Cu(II) and Fe(III)), emphasizing the importance of using site-dependent CTPs for these metals where possible. For the other metals, CTPs stayed within around 0.9 orders of magnitude, making spatial differentiation less important. In acidic waters (pH<6.4), Al(III) and Cu(II) had the highest CTPs, while Cd ranked highest in other waters. Based on the site-dependent CTPs, site-generic CTPs were developed applying different averaging principle. Emission weighted average of 7 EU-archetype CTPs was recommended as site-generic CTP for use in LCA studies, where receiving location is unclear. Compared to previous studies by Gandhi et al. (2010, 2011a), new site-dependent CTPs were similar or slightly higher for Cd, Co, Ni, Pb and Zn, but 1–2 orders of magnitude higher for Cu. Compared to the default site-generic CTPs in the frequently used characterization models USES-LCA and USEtox, new site-generic CTPs were mostly higher or similar, within up to ∼2 orders of magnitude difference.

Uncertainty and spatial variability in characterization factors for aquatic acidification at the global scale

Purpose Characterization factors (CFs) quantifying the potential impact of acidifying emissions on inland aquatic environments in life cycle assessment are typically available on a generic level. The lack of spatial differentiation may weaken the relevance of generic CFs since it was shown that regional impact categories such as aquatic acidification were influencedbythesurroundingsoftheemissionlocation.Thispaper presents a novel approach for the development of spatially differentiatedCFsata globalscalefor theaquatic acidification impact category. Methods CFs were defined as the change in relative decrease of lake fish species richness due to a change in acidifying chemicals emissions. The characterization model includes the modelling steps linking emission to atmospheric acid deposition (atmospheric fate factor) change, which lead to lake H + concentration (receiving environment fate factor) change and a decrease in relative fish species richness (effect factor). We also evaluated the significance of each factor (i.e. atmospheric fate, receiving environment fateand effects)tothe overall CFs spatial variability and parameter uncertainty. Results and discussion The highest CFs were found for emissions occurring in Canada, Scandinavia and the northern central Asia because of the extensive lake areas in these regions (lake areas being one of the parameters of the CFs; the bigger the lake areas, the higher the CFs). The CFs’spatial variability ranged over 5, 6 and 8 orders of magnitude for NOx ,S O2 and NH3 emissions, respectively. We found that the aquatic receiving environment fate factor is the dominant contributor to the overall spatial variability of the CFs, while the effect factors contributed to 98 % of the total parameter uncertainty.

Development of USEtox characterisation factors for dishwasher detergents using data made available under REACH

Because of the more and more stringent regulations and customer demand, dishwasher detergent manufacturers are constantly improving the composition of the products towards better environmental performances. In order to quantify the pros and cons of these changes on the lifecycle of detergents, as compared to conventional products, the use of Life Cycle Assessment (LCA) is a meaningful opportunity. However, the application of the methodology is hampered by the lack of Characterisation Factors (CFs) relative to the specific chemical substances included in the detergents composition, which cannot be included in the impact assessment of the effluent discharge. In this study we have tackled this problem, taking advantage of the specific case of three dishwasher detergents produced by the Chemolux/McBride group: phosphate-based, eco-labelled and phosphate-free formulations. Nine CFs for freshwater ecotoxicity and seven CFs for human toxicity have been developed, using the USEtox methodology and data made available under the REACH regulation. As a result, the dishwasher effluent composition could be characterised by more than 95% for freshwater ecotoxicity whereas for human toxicity the percentage was less than 36%, due to the lack of adequate and reliable repeated dose toxicity studies. The main contributing substances to freshwater ecotoxicity were found to be sodium percarbonate and sodium triphosphate, the latter confirming the pertinence of phosphates banning in the detergent industry. Regarding human toxicity, zinc shows the highest contribution. Further comparison to previous studies and sensitivity analysis substantiated the robustness of these conclusions.