Assessment of soil remediation technologies by comparing health risk reduction and potential impacts using unified index, disability-adjusted life years

The assessment methodology of soil remediation technologies including citizen's opinions about environmental policy was developed to enable direct comparison between the resident health risk reduction by carrying out remediation (decreased primary risk) and the potential impacts of chemicals emitted during the remediation on national health, social assets, and primary production (secondary risk). Both risks were quantified with an unified index, disability-adjusted life years (DALYs), by employing life cycle costing (LCC), economic input-output life cycle assessment (EIO-LCA), and life cycle impact assessment (LCIA) database. Four remediation technologies were considered: excavation-disposal, high temperature thermal desorption (HTTD), biopile, and landfarming. There was almost no difference in the decreased primary risk among the four technologies, apart from landfarming, which had the smallest decreased primary risk. The secondary risk of the biological technologies (biopile, landfarming) was smaller than that of the physical and chemical technologies (excavation-disposal, HTTD). The ratio of the decreased primary risk to the secondary risk was largest in case of landfarming, which indicated that landfarming was most effective. The sum of the residual primary risks and secondary risk was small in the biological technologies, indicating that the biological technologies had smaller environmental impacts. Indexing both of decreased primary risk and secondary risk with DALYs enables non-experts who prioritize resident's health to assess the soil remediation technologies and would facilitate the decision making in the selection of remediation technologies.