Material flow of iron in global supply chain

Recently, the issue of sustainable management of resources has been increasingly recognized. Accordingly, the issue to understand the relationship between natural resources consumption and product supply chain in the world has been also increasing. Material flow analysis (MFA) is a useful tool to understand the resource consumption and material cycle in national economy. However, detailed MFA studies of the materials embedded in foreign trade flows are rare. This study identified global trade flow of iron embedded in every bilateral trade between 231 countries by multiplying the trade volume of the commodity in BACI (Base pour l'Analyse du Commerce International) database and the iron content of each commodity. Moreover, we focused on the case of Japan, China, and United State, and estimated each mass of iron embedded in the imports and export. The identified total flows of iron embedded in international trade is 1.15×10⁹ t-Fe, and 35.2% of the flows is concentrated in three countries, which is Japan, China and United State known as crude steel production countries.