Comparison of environmental impact and external cost assessment methods

Background, aim, and scopeImpact assessment can be completed with the help of Life Cycle Impact Assessment (LCIA) as a part of Life Cycle Assessment (LCA) and External Cost Assessment methods. These methods help, for project and product classifications, to protect human health and the environment. Comparison of different impact assessment methods along parallel evaluations of real air pollution case studies helps to detect similarities and dependencies between them. The comparison helps and supports the work in both areas by mutually exploiting the merits of both methods. On the other hand, the detected similarities and dependencies also support the accuracy of the assessment work.Materials and methodsTwo impact assessment methods are compared to detect the dependencies between them. These are: the damage-oriented Life Cycle Impact Assessment method Eco-indicator 99 (EI99) and the Cost-Benefit Analysis (CAFE CBA) carried out within the framework of the Clean Air for Europe Programme of the European Union. Arithmetic comparison of the two methods’ impact indicators is carried out in order to show how differently they assess and evaluate the environmental impacts of the same pollutants. Moreover, air pollution inventories of five industrialized cities in Poland are evaluated in parallel with the two impact assessment methods. The uncertainties of the two methods are also considered and Monte Carlo simulations are completed to obtain probability intervals of impact indicators and overall mean values of the generated populations.Results and discussionThe arithmetic comparison of the impact indicators shows a strict correlation between the two impact assessment methods. This correlation is confirmed by results of the parallel evaluation of the real case studies. The comparison of the overall mean values obtained by the Monte Carlo simulations also shows a clear dependency between the results of the two impact assessment methods. After detecting the dependencies between the two methods, the best guess values of the EI99 indicator are selected and applied to make a ranking of the air pollutants and their emission sources for an industrialized Polish city.ConclusionsIt can be concluded that the detected correlation between the two methods (EI99 and CAFE CBA) supports and helps the accuracy of the impact assessment. If the uncertainties of the methods are also considered, it is proved for the examples of real case studies that they correlate in their results. On the other hand, the best guess of the EI99 indicators can be used to rank emissions according to their relative damage to human health and the ecosystem, and to locate emission sources. These results help decision-makers to conclude an efficient environmental conscious policy.