In order to evaluate the effects of recycling of plastics waste, not only global environmental issues but also local environmental issues and costs should be taken into account. In this study, the following impact categories were established, i.e., global warming, resource depletion, human health, landfill capacity and costs, and a methodology for multi-aspect impact assessment of recycling of plastics waste was presented through a case study of Kawasaki City. In the case study, the following three options were compared: the status quo, where plastics waste were collected and incinerated along with combustibles; the alternative I, where plastics waste was collected separately and directly landfilled; and the alternative II, where plastics waste was collected separately and recycled in blast furnaces. Life-cycle GHG emissions and fossil fuel consumptions were estimated, and urban air pollutants emissions were converted into local residents' health damages. The results showed that recycling of plastics waste had effects on reduction of GHG emissions and fossil fuel consumptions, while the status quo was supported from the viewpoint of landfill capacity and costs. In the decision-making on separate collection and recycling of plastics waste, the results of multi-aspect impact assessment should be considered comprehensively.
Society of Environmental Science, japan