Development of Site- and Source-Specific Life Cycle Impact Assessment Methodology for Local Impact Categories in Japan
Yasunari MATSUNO, Atsushi INABA, Tateki MIZUNO
In life cycle impact assessment, the potential impact that a product or service may cause during its life cycle is evaluated. In local impact categories, such as eutrophication, photo-oxidant formation and human toxicity, the potential impact depends on the site and concentration of the substances. The contribution ratios of stationary and mobile sources to the concentration of a substance on surface significantly differ. Thus, it has been pointed out that site- and source-type-specific consideration is necessary in order to obtain meaningful results in impact assessment for local impact categories.In this work, development of site- and source-type-specific life cycle impact assessment methodology for local impact categories in Japan has been carried out. We focused on 9 substances: non-methane hydrocarbons for photo-oxidant formation; SOx, NOx, CO and SPM for human toxicity; and COD, T-P and T-N for eutrophication. Each substance was directly weighted by the distance-to-target method with normalization values and weighting factors defined separately for each site. The weighting factor for each substance was derived from the extent to which the annual average concentration of each substance deviates from the authorized standards. Population ratio in each site to the total population in Japan was alsoreflected in the weighting factor. A sourcetype- specific impact assessment methodology was proposed, in which the contribution ratios of stationary and mobile sources to the concentration of a substance on surface were considered in inventory analyses and normalization values.