User needs analysis and development of priorities for life cycle impact assessment

The development of the LCIA programme of the UNEP/SETAC Life Cycle Initiative started with a global survey of LCA practitioners. There were 91 LCIA-specific responses from all global regions. Respondents gave an indication of how they use LCA with respect to both the stage of LCA that they base decisions on (LCI, LCIA or a combination of both) as well as the types of decisions which they support with LCA information. The issues requiring immediate attention within the UNEP SETAC Life Cycle Initiative identified from this User Needs analysis are the need for transparency in the methodology, for scientific confidence and for scientific co-operation as well as the development of a recommended set of factors and methodologies. Of interest is the fact that results from the different regions highlighted the need for different impact categories. Based on this information proposals were made for new impact categories to be included in LCA (and thus LCIA). The LCIA programme aims to enhance the availability of sound LCA data and methods and to deliver guidance on their use. More specifically, it aims to 1) make results and recommendations widely available for users through the creation of a worldwide accessible information system and 2) establish recommended characterisation factors and related methodologies for the different impact categories, possibly consisting of sets at both midpoint and damage level. The work of the LCIA programme of the UNEP/SETAC Life Cycle Initiative has been started within four task forces on 1) LCIA information system and framework, 2) natural resources and land use, 3) toxic impacts, and 4) transboundary impacts. All participants willing to contribute to these efforts are invited to contact the LCIA programme manager or to join the next LCIA workgroup meeting that will take place in at the world SETAC congress in Portland on Thursday 18 November 200

Continent-specific Intake Fractions and Characterization Factors for Toxic Emissions: Does it make a Difference?

-: DOI: http://dx.doi.org/10.1065/lca2006.04.012 Goal and Scope: This paper aims to develop continental characterization factors for the human toxicity impacts of emissions released to air in different continents and to analyze under which conditions this spatial distinction makes a significant difference compared to generic characterization factors. Methods: The IMPACT 2002 multimedia and multipathways model has been parameterized to define 6 continental box-models, each of them nested in a world box in order to capture impacts of emissions leaving the initial continent. Applying the model to a test set of 31 heterogeneous chemicals emitted to air, intake fractions and human toxicity characterization factors were calculated for each continent and compared. Results and Discussion: For a given chemical, characterization factors can vary of typically a factor 5 to 10 between continents (max 102), mainly as a function of population density for inhalation and as a function of the total agriculture production per km2 for ingestion. This is significant but still limited compared to the variation between substances, of 106 in intake fraction and of 1012 in cumulative risks. Conclusion: The variation amplitude is limited for persistent chemicals and decreases with the fraction of the chemical advected out of the continent. Moreover, the ranking between continents remains almost the same for all chemicals. Therefore generic characterization factor for air emissions calculated at continental level, such as the one proposed by the common life cycle assessment method, are in most cases suitable for comparative purposes in any other continent. However, continent specific characterization factors are required if one is interested in evaluating absolute values or in comparing impact between scenarios with emissions in very different continents. For this purpose, a simplified but accurate correlation is determined to extrapolate continent specific intake fractions and characterization factors of a wide range of substances for Oceania, Africa, South America, North America and Asia, starting from the results of Europe as a base continent. -: Recommandation and Perspectives. Further research should focus on linking the different continental boxes to obtain a global spatial model including major climatic phenomenon such as the air transport by jet stream. The level of spatial resolution, however, has to be carefully selected to capture significant differences, but at the same time to avoid unnecessarily requirement efforts for data gathering and calculation capabilitie

Etude de la contagion sur les marchés actions

Ce travail a pour but de mettre en évidence la nécessité de l’analyse en continu des coefficients de corrélation dans le but de prévenir le risque systémique. Dans un premier temps, on verra les fondements théoriques qui ont articulé la réflexion constituant la genèse de ce travail. Dans un deuxième temps, grâce à deux exemples, on verra comment l’étude des co-mouvements peut permettre d’observer l’effet de contagion sur les marchés actions. Finalement, des potentielles applications de l’analyse des coefficients de corrélation seront mises en avant. Par cette démarche, on constatera que l’observation des mouvements joints par le biais de l’analyse technique, peut permettre de déceler des opportunités d’investissements

Fate coefficients for the toxicity assessment of air pollutants

The inclusion of fate and exposure is a central issue in Life Cycle Impact Assessment (LCIA). According to the framework developed by the Society of Environmental Toxicity and Chemistry (SETAC), fate and exposure route are included through a fate coefficient which makes the link between an emission and the related increase in concentration. In the Critical surface-time 95 methodology, fate factors of air pollutants are determined empirically at a world level as the ratio of measured concentration to the total estimated emission flow. Based on a detailed study performed for seventeen pollutants, a correlation is developed to predict fate factors from the residence time. Variation of a factor 10000 arc observed for the fate coefficient. Empirical fate factors are compared to modelled fate factors and are found to have a similar order of magnitud

A quantitative structure‐property relationship (QSPR) for estimating solid material‐air partition coefficients of organic compounds

The material‐air partition coefficient (Kma) is a key parameter to estimate the release of chemicals incorporated in solid materials and resulting human exposures. Existing correlations to estimate Kma are applicable for a limited number of chemical‐material combinations without considering the effect of temperature. The present study develops a quantitative structure‐property relationship (QSPR) to predict Kma for a large number of chemical‐material combinations. We compiled a dataset of 991 measured Kma for 179 chemicals in 22 consolidated material types. A multiple linear regression model predicts Kma as a function of chemical’s Koa, enthalpy of vaporization (∆Hv), temperature, and material type. The model shows good fitting of the experimental dataset with adjusted R2 of 0.93 and has been verified by internal and external validations to be robust, stable and has good predicting ability (Rext2 > 0.78). A generic QSPR is also developed to predict Kma from chemical properties and temperature only (adjusted R2 = 0.84), without the need to assign a specific material type. These QSPRs provide correlation methods to estimate Kma for a wide range of organic chemicals and materials, which will facilitate high‐throughput estimates of human exposures for chemicals in solid materials, particularly building materials and furniture.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146827/1/ina12510.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146827/2/ina12510_am.pd

How does iso/dis 14042 on life cycle impact assessment accommodate current best available practice?

This article discusses to which extent the forthcoming ISO standard on life cycle impact assessment (ISO/DIS 14042) will be able to accommodate current best available practice in this field. There is, particularly, the risk that the requirement of scientific validity for public comparative assertions cannot be met sufficiently so that the standard may become counterproductive. It is concluded that current best practice for most of the impact categories is compatible with the forthcoming standard. However, difficulties will arise with the toxicity categories, in particular with human toxicity. There is no encompassing indicator is available which does not involve weighting between subcategories. A major improvement would be if, for weighting within categories, internationally accepted value choices would be established as a sufficient condition for public comparative assertion