Evaluation of characterization models for the photochemical smog impact category focused on the Brazilian reality

Abstract

The Life Cycle Impact Assessment (LCIA) is composed of characterization models, and in Brazil, the methodological and scientific LCIA framework is still under development. The research’s aim was to evaluate the literature available characterization models to photochemical smog category. Thus, the contribution of work is recommending one of these models to be used in Brazilian LCA studies, standardizing the studies in Brazil. The methodology consisted of searching the literature and selecting, describing and analyzing the characterization models as well as elaborating a table of criteria for better comparison. Aiming to visualize the differences in the results of each selected model, a case study was applied to analyze the photochemical smog formation potential to the transport of one ton of sugar using two transportation modes (road and railroad). Five characterization models related to smog category were selected, described and compared. Herewith, it was observed that the models present significant differences, that is, each model presents Characterization Factors (CF) for different categories within the environmental impact chain of the photochemical smog (midpoint and/or endpoint), differences in modeling, scale of the model (regional, continental or global), quantity and quality of elementary flows, etc. Those factors have influence in the CF’s calculation and, consequently, the LCA’s results, in the same case study. The criteria table’s results suggested that the model of Van Zelm et al. (2016) – World (midpoint and endpoint), is the best interim option to be used in studies of LCA in Brazil, because it was the model that resulted in the highest grade referring to the established criteria and it presents results on a Global scale. However, the results do not rule out the need for regionalization studies, which would develop a model that presents results and studies directed to the Brazilian reality or adjust the model of Van Zelm et al. (2016) - Brazil