Site-dependent life-cycle impact assessment in Sweden

Goal, Scope and Background. Although LCA is traditionally a site-independent tool, there is currently a trend towards making LCA more site-dependent if not site-specific. For Europe, site-dependent impact factors have been calculated on a country basis for acidification, terrestrial eutrophication and toxicological impacts. It is, however, an open question whether this is the Optimum level for site-dependent factors. The aim of this paper is to develop site-dependent characterisation factors for different parts of Sweden for air emissions of NO., SO and particulates regarding ecosystem and human health impacts. Based on experiences from a case-study, the usability of the site-dependent factors for LCA are discussed, as well as the appropriate level of site-dependency for ecosystem and human health impacts. Methodology. The Ecosense model is used for calculating site-dependent factors for some atmospheric pollutants. Characterisation factors are calculated for four different places in Sweden with two different stack heights. Results and Conclusions. The characterisation factors for ecosystem impacts show fairly small differences between different parts of Sweden (within a factor of two). For health impacts, the differences between different parts of the country were larger and more significant (up to one order of magnitude). Also the difference between low and high stack heights may be relevant, especially in densely populated areas. These results suggest that for ecosystems, site-dependent characterisation factors for the considered atmospheric pollutants on a country level may be sufficient for most applications. However, for health impacts, site-dependent factors on a country level may be inappropriate. Beside LCA, the calculated factors and the methodology used should also be useful for other environmental system analysis tools, such as Strategic Environmental Assessment, Cost-Benefit Analysis and Environmental Management Systems.