Holistic Environmental Health Impact Assessment: Hybridisation of Life Cycle Assessment and Quantitative Risk Assessment using Disability Adjusted Life Years

Life cycle assessment (LCA) and quantitative risk assessment (QRA) are environmental management tools commonly used to evaluate potential human health impacts associated with proposed or existing infrastructure and products. Each approach has distinct objectives and, consequently, their conclusions may be inconsistent or contradictory. On the other hand, due to their somewhat complimentary differences, it has been recognised that the integration of LCA and QRA may provide a more holistic approach to environmental health impact assessment. In this research, the development and evaluation of a hybrid application of LCA and QRA, using disability adjusted life years (DALYs) as a common metric, is described. An extensive analysis of the use of DALYs in LCA methods was conducted to examine whether the emerging use of DALYs in LCA has the potential to be compatible with the more established use of DALYs for QRA. The ability to merge the two approaches through the combined use of DALYs was then investigated using two contrasting test applications. These were a large-scale water recycling project in Sydney, Australia and future air quality policy evaluation in Victoria, Australia. A comparative analysis of multiple scenarios for each application was undertaken for this purpose.Through these examples, the relationships and potential trade-offs between local and global impacts, which could have been overlooked without the proposed approach, were identified. The advantages of providing a more comprehensive assessment of human burden of disease for the alternative scenarios, in particular, the importance of considering the results of both LCA and QRA in a comparative assessment of decision alternatives to avoid problem shifting, were demonstrated. The application of DALYs as a common measure between the two approaches was confirmed to be applicable and highly useful for this purpose