日本における鉛のマテリアルフロー・ストック分析

抄録

We conducted Material flow/stock analysis, in order to estimate not only the in-use stock, but also waste flows of lead in Japan. Material flow analysis (MFA) quantifies flows of materials into, out of a system boundary. In this paper, all lead flows are captured throughout its lifecycle; from Raw Material Production, Material Production, Interim Product Production, Final Product Production, Use, to Waste management including Recycling. There are two motivations why we focused on lead. The first is that when exports of lead old scraps rapidly increased in 2005, changes of lead old scraps exports affect domestic lead refineries. This incident suggests the importance of analyzing the scrap trade flows. The second is its toxicity. This means the importance of appropriate management of waste flows. Currently, 80% of lead is being used as lead-acid batteries. As a consequence of MFA, We find that the stock of in-use lead in Japan is about 1.58 million tonnes in 2007. The batteries for Four-wheel cars (34%) and other vehicles (19%) are biggest form of lead in-use stock, followed by the stock in construction (18%) .