Expanded Damage Function of Stratospheric Ozone Depletion to Cover Major Endpoints Regarding Life Cycle Impact Assessment (12 pp)

Background Stratospheric ozone depletion is one of the important environmental issues for LCIA. The National LCA Project of Japan has developed a framework of LCIA since 1998, which tackles the issue employing an endpoint approach. Although the basic components were available in 2000, it was required that the target endpoints should be expanded in particular. Objective This study aimed at expanding the scope of damage function of ozone depletion in the LCIA framework of LIME. Damage function gives potential and quantitative damage for each endpoint per unit emission of ODS. Methods Marginal damage due to the unit emission of ODS was calculated for 13 substances for which quantitative information was available as follows: (1) the increase of UVB radiation at the earth's surface per unit emission of ODS was estimated, (2) the increase of potential damage per unit increase of UVB radiation was estimated, (3) the increase of potential damage per unit emission of ODS was determined by connecting the two relationships, and (4) correcting by the atmospheric lifetime of ODS, so that the damage function was then obtained. For other ODSs regulated by the Montreal Protocol, their damage functions were estimated by multiplying the ratio of ODP compared to the corresponding reference substance by the damage function of this reference substance. Results and Discussion The damage function of ozone depletion included the following endpoints: skin cancer and cataract for human health, crop production and timber production for social assets, and terrestrial NPP and aquatic NPP for primary productivity. And damage factors for each safeguard subject were also obtained. Conclusion The damage function of ozone depletion could cover all ODSs regulated by the Montreal Protocol and also cover important endpoints. Uncertainty of damage function is also an important point to be elucidated. Preliminary studies of uncertainty analysis have begun for the damage function of ozone depletion. However, further analysis is required to comprehensively evaluate the uncertainty of the damage function. - Abbreviations: BCC-Basal Cell Carcinoma; CFC-Chlorofluorocarbon; DALY-Disability Adjusted Life Years; DF-Damage Factor; DI-Damage Indicator; EESC-Equivalent Effective Stratospheric Chlorine; HBFC-Hydrobromofluorocarbon; HCFC-Hydrochlorofluorocarbon; LCA-Life Cycle Assessment; LCIA-Life Cycle Impact Assessment; LIME-Life-cycle Impact assessment Method based on Endpoint modeling; MM-malignant melanoma; NPP-Net Primary Production; ODP-Ozone Depletion Potential; ODS-Ozone Depleting Substance; SCC-Squamous Cell Carcinoma; TCL-Tropospheric Chlorine Loading; UVB-Ultraviolet B; YLD-Years of Life Disabled; YLL-Years of Life Lost.     

Development of damage function of acidification for terrestrial ecosystems based on the effect of aluminum toxicity on net primary production

Background  Acidification is one of the important impact categories for life cycle impact assessment. Although its characterization has progressed during this decade through the employment of midpoint approaches, only limited studies of endpoint approaches have been performed. Objective. This study aimed at developing damage function of acidification for terrestrial ecosystems in Japan. Damage function expresses a quantitative relationship between the inventory and endpoint damage. Methods  The geographical boundary was limited in Japan both for emission and impact. In this study, sulfur dioxide (SO₂), nitrogen monoxide (NO), nitrogen dioxide (NO₂) (NO and NO₂ collectively mean NO_x), hydrogen chloride (HC1), and ammonia (NH₃) were considered as major causative substances of acidification. Net primary production (NPP) of existing vegetation was adopted as an impact indicator of terrestrial ecosystems. The aluminum toxicity was adopted as the major factor of effect on terrestrial ecosystems due to acidification. The leachate concentration of monomeric inorganic aluminum ions was selected to express the plant toxicity of aluminum. Results and Discussion  The results of damage function gave utilizable factors both for a midpoint approach and an endpoint approach; Atmospheric Deposition Factor (ADF) and Damage Factor (DF) applicable to the former and the latter, respectively. The ADF indicates an increase of H⁺ deposition per unit area to an additional emission of causative sustance. The additional emission corresponds to some alternatives in industry, not the baseline emission. The DF indicates the total NPP damage in all of Japan due to the additional emission of causative substances. The derived NPP damage is on the order of one millionth of the NPP itself. HC1 and NH3 showed larger ADFs and DFs than that of SO₂ and NO_x. The reason was ascribed to the relatively large source-receptor relationships (SRR) of HC1 and NH₃. However, since the method applied to determine the SRR of HC1 and NH₃ has larger uncertainties than that of SO₂ and NO_x, attention is needed to handle the difference. Conclusion  The damage function easily defines the concrete NPP damage due to an additional emission. The impact indica tor, NPP, also has an advantage in its mass unit that is directly summable through the entire impact categories. Expansion of endpoints, such as in aquatic ecosystems, material degradation, human health, and biodiversity aspects of terrestrial ecosystems, is an important subject for future work. Further, uncertain analyses for major parameters will provide helpful information on the reliability of damage function.     

Evaluating the variability of aquatic acidification and photochemical ozone formation characterization factors for Canadian emissions

Background, aim, and scope  The Canadian life cycle impact assessment method LUCAS proposes a characterization of the impact categories aquatic acidification and photochemical ozone formation using a resolution scale based on 15 terrestrial ecozones. Each ecozone represents areas of the country which can be identified easily by general living (biotic) and nonliving (abiotic) characteristics. The three main purposes of this research are to improve the characterization models of both impact categories including regional exposure and effect factors, to investigate what is the best resolution scale between Canadian provinces or ecozones, and to analyze the extent of spatial variability. Materials and methods  A model framework accounting for variability in fate, exposure and effect factors has been elaborated. The same fate factor, based on Advanced Statistical Trajectory Regional Air Pollution matrices, applies to both impact categories. For the aquatic acidification impact category, the fate factor also accounts for the fraction of the deposition transferred to the aquatic ecosystem. The exposure factor for this impact category is considered to be 1 and the effect factor is based on the critical load exceedance, where the potential impacts are only considered in provinces or ecozones in which the critical load is exceeded. For the photochemical ozone formation impact category, the exposure factor is considered to be proportional to the population density in each province or ecozone, and the effect factor is represented by the chemical reactivity estimated with the maximum incremental reactivity model. The calculation of the new characterization factors using both a province-based and ecozone resolution scale was performed using a matrix which converts data from one resolution scale to another. Results  Results with the inclusion of the effect and the exposure factors show that the spatial variability between provinces remains within a factor of 10 and 5 for aquatic acidification and photochemical ozone formation, respectively. Discussion  Analysis of the results show that regionalization by province is preferable to regionalization by ecozone. It is more accurate in regard to atmospheric modeling and more representative of population distribution. However, averaging the fate factor and the population density over a whole province results in a serious limitation. Conclusions  The spatial variability of characterization factors between provinces is in the same order of magnitude as the overall range between chemicals for aquatic acidification while much smaller for photochemical ozone formation. Hence, at this stage of knowledge, province-based regionalization seems to be more relevant for the aquatic acidification impact category than for photochemical ozone formation. Recommendations and perspectives  Research must be pursued to integrate a better transport and deposition model with improved spatial capabilities and a successive modeling step properly describing the cause–effect chain up to the damage level, such as the biotic environment and the human population.     

Characterisation and Normalisation Factors for Life Cycle Impact Assessment Mined Abiotic Resources Categories in South Africa: The manufacturing of catalytic converter exhaust systems as a case study (10 pp)

Goal and Background Current Life Cycle Impact Assessment (LCIA) procedures have demonstrated certain limitations in the South African manufacturing industry. The aim of this paper is to propose new characterisation and normalisation factors for classified mined abiotic resource depletion categories in the South African context. These factors should reflect the importance of mined resources as they relate to region-specific resource depletion. The method can also be applied to determine global factors. Methods The reserve base (as in 2001) of the most commonly produced minerals in South Africa is used as basis to determine characterisation factors for a non-renewable mineral resources category. The average production of these minerals from 1991 to 2000 is compared to economically Demonstrated and Demonstrated Marginal Reserves (and not ultimate reserves) to obtain the characterisation factors in equivalence units, with platinum as the reference mineral. Similarly, for a non-renewable energy resources category, coal is used in South Africa as equivalent unit as it is the most important fossil fuel for the country. Crude oil and natural gas resources are currently obtained from reserves elsewhere in the world and characterisation factors are therefore determined using global resources and production levels. The normalisation factors are based on the total economic reserves of key South African minerals and world non-renewable energy resources respectively. A case study of the manufacturing of an exhaust system for a standard sedan is used to compare LCIA results for mined abiotic resource categories that are based on current LCIA factors and the new South African factors. Results and Discussion The South African LCIA procedure differs from current methods in that it shows the importance of other mined resources, i.e. iron ore and crude oil, relative to PGMs and coal for the manufacturing life cycle of the exhaust system. With respect to PGMs, the current characterisation factors are based on the concentrations of the metals in the ores and the ultimate reserves, which are erroneous with respect to the actual availability of the mineral resources and the depletion burden placed on these minerals is consequently too high. Conclusions The South African LCIA procedure for mined abiotic resources depletion shows the significance of choosing a method, which is inline with the current situation in the mining industry and its limitations. Recommendations and Outlook It is proposed to similarly investigate the impacts of the use of other natural resource groups. Water, specifically, must receive attention in the characterisation phase of LCIAs in South African LCAs.     

Evaluation of Ecotoxicity Effect Indicators for Use in LCIA (10+4 pp)

Goal, Scope and Background The paper describes different ecotoxicity effect indicator methods/approaches. The approaches cover three main groups, viz. PNEC approaches, PAF approaches and damage approaches. Ecotoxicity effect indicators used in life cycle impact assessment (LCIA) are typically modelled to the level of impact, indicating the potential impact on 'ecosystem health'. The few existing indicators, which are modelled all the way to damage, are poorly developed, and even though relevant alternatives from risk assessment exist (e.g. recovery time and mean extinction time), these are unfortunately at a very early stage of development, and only few attempts have been made to include them in LCIA. Methods The approaches are described and evaluated against a set of assessment criteria comprising compatibility with the methodological requirements of LCIA, environmental relevance, reproducibility, data demand, data availability, quantification of uncertainty, transparency and spatial differentiation. Results and Discussion The results of the evaluation of the two impact approaches (i.e. PNEC and PAF) show both pros and cons for each of them. The assessment factor-based PNEC approaches have a low data demand and use only the lowest data (e.g. lowest NOEC value). Because it is developed in tiered risk assessment, and hence makes use of conservative assessment factors, it is not optimal, in its present form, to use in the comparative framework of LCIA, where best estimates are sought. The PAF approaches have a higher data demand but use all data and can be based on effect data (PNEC is no-effect-based), thus making these approaches non-conservative and more suitable for LCIA. However, indiscriminate use of ecotoxicity data tends to make the PAF-approaches no more environmentally relevant than the assessment factor-based PNEC approaches. The PAF approaches, however, can at least in theory be linked to damage modelling. All the approaches for damage modelling which are included here have a high environmental relevance but very low data availability, apart from the 'media recovery-approach', which depends directly on the fate model. They are all at a very early stage of development. Conclusion Recommendations and Outlook. An analysis of the different PAF approaches shows that the crucial point is according to which principles and based on which data the hazardous concentration to 50% of the included species (i.e. HC50) is estimated. The ability to calculate many characterisation factors for ecotoxicity is important for this impact category to be included in LCIA in a proper way. However, the access to effect data for the relevant chemicals is typically limited. So, besides the coupling to damage modelling, the main challenge within the further development and improvement of ecotoxicity effect indicators is to find an optimal method to estimate HC50 based on little data.     

Estimates of real damage from air pollution: Site dependence and simple impact indices for LCA

In contrast to the various “potential impact” indices that have been proposed, we show that indices for real damage can be derived, based on the impact pathway methodology which involves the calculation of increased pollutant concentration in all affected regions due to an incremental emission (e.g. μg/m³ of particles, using models of atmospheric dispersion and chemistry), followed by the calculation of physical impacts (e.g. number of cases of asthma due to these particles, using a concentration-response function). The numbers are summed over all receptors of concern (population, crops, buildings,…). We show that in a uniform world (linear dose-response function, uniform receptor density and uniform atmospheric removal rate) the conservation of matter implies a very simple formula for the total damage. The generalization to secondary pollutants is straightforward. By detailed numerical evaluations, using real data for atmospheric dispersion and geographic receptor distribution, we have demonstrated that this simple formula is an excellent representation of typical damages. Results are shown for the principal air pollutants emitted by smoke stacks of industrial installations or by road transport. A preliminary version was presented as a key note lecture at the SETAC Meeting in Bordeaux, April 14-18, 1998     

Anaerobic digestion of starch-polyvinyl alcohol biopolymer packaging: biodegradability and environmental impact assessment

The digestibility of a starch-polyvinyl alcohol (PVOH) biopolymer insulated cardboard coolbox was investigated under a defined anaerobic digestion (AD) system with key parameters characterized. Laboratory results were combined with industrial operational data to develop a site-specific life cycle assessment (LCA) model. Inoculated with active bacterial trophic groups, the anaerobic biodegradability of three starch-PVOH biopolymers achieved 58-62%. The LCA modeling showed that the environmental burdens of the starch-PVOH biopolymer packaging under AD conditions on acidification, eutrophication, global warming and photochemical oxidation potential were dominated by atmospheric emissions released from substrate degradation and fuel combustion, whereas energy consumption and infrastructure requirements were the causes of abiotic depletion, ozone depletion and toxic impacts. Nevertheless, for this bio-packaging, AD of the starch-PVOH biopolymer combined with recycling of the cardboard emerged as the environmentally superior option and optimization of the energy utilization system could bring further environmental benefits to the AD process.