Tracking the Product Origins of Waste for Treatment Using the WIO Data Developed by the Japanese Ministry of the Environment

Almost any production and consumption activity generates waste directly or indirectly over its supply chain. This paper is concerned with identifying the product origins of waste or waste footprint of products. It uses the waste input-output (WIO) data recently developed and published by the Japanese Ministry of the Environment (MOE), which is, to date, one of the publicly available WIO data with the highest resolution in products and waste. Results show that footprint calculation can identify factors behind the waste flows that otherwise would not be recognizable. The amount of waste for landfill is smaller than that for incineration only because around 80% of potential waste for landfill, mostly construction waste, is absorbed by recycling, attributed to public capital formation. Without this massive demand for recycling, the amount of waste sent to landfill would have been five to six times larger than the actual one, exceeding incineration. Footprint analysis of plastic waste reveals that targeting only postconsumer plastics waste is misleading, because most plastics waste has its origins in production. Service industries are found to be a major contributor to waste incineration and landfill in terms of footprint, whereas their contribution is minor in direct discharge.