Kenichi Nakajima

National Institute for Environmental Studies

Objectives: To validate the upper thresholds of the thermal safety guidelines for multiple outdoor sports in terms of heat illness risk. Methods: The reproducibility of the joint system thermoregulation model (JOS-3) of core temperature has been validated for 18 sports experiments (n=213) and 11 general exercise experiments (n=121) using the Bland–...

Achieving a zero-emission future depends greatly on how steel production is decarbonized within a limited time frame. Here we show that the production of zero-emission steel is possible but that the quantity and quality of steel may be limited by scrap downcycling. Using Japan as a case study, our analysis shows that most steel scrap is currently d...

The increased research attention on estimating the global mercury use and emissions in artisanal and small-scale gold mining (ASGM) has improved awareness of the problems associated with ASGM. However, little attention has been paid to the specific effects of particular intervention strategies to mitigate global mercury use and emissions in accorda...

The ongoing international movement to phase out mercury, mainly led by the Minamata Convention on Mercury, raises concerns about illegal intercountry trade, including smuggling. This study aims to detect the existence of illegal intercountry mercury trade under the social mercury phase-out movement, focusing on discrepancies in each country's trade...

Production and services are supported by fixed-capital which require large amounts of material investments. Given that material use triggers substantial carbon emissions, management of the material use and carbon emissions via fixed-capital formation is vital for climate targets. Here, we calculate capital-embodied material footprints (MFs) and the...

In 2017, the Minamata Convention (MC) on mercury (Hg) control entered into force. However, whether the MC is effective and how it reshapes the global Hg flow remain unclear. In this study, we established a method to detect inconsistencies in data on global Hg trade, and calculated the gap between the demand and supply of Hg to the artisanal and sma...

Moving towards a 1.5 °C world could fundamentally alter the future copper cycle through two key drivers: the implementation of decarbonization technologies and the imposition of an emissions budget on production activities. This study explores the impact of these drivers on the global copper cycle using a dynamic material flow analysis, coupled wit...

There are concerns about the impact of climate change on Olympic Games, especially endurance events, such as marathons. In recent competitions, many marathon runners dropped out of their races due to extreme heat, and it is expected that more areas will be unable to host the Games due to climate change. Here, we show the feasibility of the Olympic...

In recent years, there has been concern about the increase in flood risks due to climate change, and the revision of flood control plans towards climate change has become a severe challenge. In this study, in order to understand the changes in the risk that have already occurred, we quantitatively analyzed the trends of changes in heavy rainfall le...

The United Nations Environment Programme has specifically identified the main causes of mercury accumulation in surface soils and the oceans to be closely linked to anthropogenic mercury emissions and releases. While appropriate implementation of the Minamata Convention on Mercury (effective since 16 August 2017) is expected to reduce global supply...

There are concerns about the impact of climate change on Olympic Games, especially endurance events, such as marathons. In recent competitions, many marathon runners dropped out of their races due to extreme heat, and it is expected that more areas will be unable to host the Olympic Games due to climate change. Here, we show the feasibility of the...

The global transition to fundamentally decarbonized electricity and transport systems will alter the existing resource flows of both fossil fuels and metals; however, such a transition may have unintended consequences. Here we show that the decarbonization of both the electricity and transport sectors will curtail fossil fuel production while parad...

Because of increased heavy rainfall that is occurring along with climate change, some concern exists that damage caused by river flooding will spread. Countermeasures against damage are urgently needed. However, increased heavy rainfall along with climate change and the degree of current countermeasures differ depending on the river. The necessity...

Remanufacturing gives a full new service life for every usage cycle of a product. Since remanufacturing avoids material dissipation, it is conceivably superior to material recycling. However, quantifying the effectiveness of remanufacturing is difficult due to the fundamental lack of indicators and supporting tools designed for the task. In this st...

The foundations of modern society are based on metals, yet their production is currently placing considerable strain on the Earth’s carrying capacity. Here, we develop a century-long scenario for six major metals (iron, aluminum, copper, zinc, lead, and nickel) harmonized with climate goals, with the goal of establishing science-based targets. We s...

Human beings have created a vast social infrastructure, which means that the successful achievement of the UN Sustainable Development Goals and implementation of the Paris Agreement will require technologies utilizing vast quantities of a wide range of natural resources. It is, therefore, essential to gain a more holistic understanding of stock–flo...

Sustainable metal supply requires well-coordinated strategy and policy packages based on a sound scientific understanding of anticipated long-term demand, supply, and associated environmental implications. Such information , however, is highly fragmented among various case studies. Accordingly, this extensive review explores the projected long-term...

Metal consuming countries depend on mining activity in other countries, which may impose potential pressure on sustainable metal supply. This study proposes an approach to analyze the responsibility of consuming countries for mining activities based on the decomposition analysis of scarcity-weighted metal footprints (S-MFs) of Japan. The applicatio...

Metals underpin essential functions in modern society, yet their production currently intensifies climate change. This paper develops global targets for metal flows, stocks, and use intensity in the global economy out to 2100. These targets are consistent with emissions pathways to achieve a 2 °C climate goal and cover six major metals (iron, alumi...

Contamination with tramp elements is a major concern in steel recycling. This study aimed to identify the influence of impurity elements on the major properties of carbon steel. The content of impurity elements in recycled steel was determined via elemental analysis of randomly sampled steel bars. Of the 23 impurity elements considered, 15 were fou...

Critical metals are technologically vital to the functionality of various emerging technologies, yet they have a potentially unstable supply. This condition calls for strategic planning based on the expected long-term demand and supply of these metals and the implications attached. Here, we provide the first systematic review of studies (88 studies...

Electrification of the transport sector will support its decarbonization, yet significantly change material requirements. This calls for an integrated modeling approach internalizing metal demand-supply dynamics in low-carbon scenarios to support the Paris agreement on climate change and sustainable material circulation. Here we develop a step towa...

This study investigates, at the country level, the adverse effects of changes in metal inputs on the achievement of sustainable development goals (SDGs). It also highlights the relationships between metals use and various socioeconomic consequences that urgently require decoupling in order to achieve the SDGs. We performed panel data analysis to ev...

An optimum treatment system for the waste electronic home appliance in remote area by local pre-processing and outsourcing post-processing is proposed. The cost reduction potential of the proposed treatment system is presented for main four types of electronic home appliances by the case study of Kinmen, Taiwan. Implementation of local pre-processi...

Remanufacturing is an industrial process that turns used products into new ones with the same quality, functionality, and warranty as new products; it is a critical element for realizing a resource-efficient manufacturing industry and a circular economy. Remanufacturing may involve adding new and better functionality to used products, such as addin...

According to the concept of a circular economy, further promotion of reuse and recycling might aid in closing the loop. However, material recycling may cause various types of material losses due to thermodynamic limitations and product complexity. In this study, we focused on automobile engines and their reuse, with the aim of quantifying the amoun...

In today’s global economy, sustainable resource management requires a consumption perspective of resource use and insight into actual resource use through the global supply chain. The estimated global amount of used and unused extraction caused by mineral extraction of iron, copper, and nickel more than doubled from 1990 to 2013 (iron: 2.8 to 6.7 P...

The abandoned end-of-life vehicle (ELV) problem in small islands has negative effects on local sustainable development, and the treatment of ELVs in island scale is usually difficult. This study presents the investigation of the material flows and economic analysis on the ELVs in small islands by the case study of Kinmen, Taiwan. The ELVs generatio...

Case studies of nickel mines in New Caledonia revealed significant differences among mining sites even though the mines host the same type of nickel laterite ore deposit and employ the same open-cut mining method. The intensity of land use change was evaluated as the area of land use change per unit of metal contained in extracted ores. Among the s...

Environmental Product Declarations (EPDs) are used to communicate product's environmental performances to relevant stakeholders, whereas Product Category Rules (PCRs) provide guidelines for making EPDs in different product categories. Little is known regarding the cost for developing EPDs and PCRs. We therefore conducted an international survey, an...

Importance of end-of-life vehicles (ELVs) as an urban mine is expected to grow, as more people in developing countries are experiencing increased standards of living, while the automobiles are increasingly made using high-quality materials to meet stricter environmental and safety requirements. While most materials in ELVs, particularly steel, have...

Economic growth and sometimes the use of green technologies have been associated with a rapid rise in the use of metals and minerals. In today's globalized economy, natural resource consumption influences environmental impacts far removed from the place of consumption. Knowledge about the flow of substances is fundamental to reducing natural resour...

Alloying metals are indispensable ingredients of high quality alloy steel such as austenitic stainless steel, the cyclical use of which is vital for sustainable resource management. Under the current practice of recycling, however, different metals are likely to be mixed in an uncontrolled manner, resulting in function losses and dissipation of met...

In this study, the elemental distribution of 26 elements in a ferronickel electric furnace was thermodynamically analyzed to determine the removability of impurities from secondary resources during smelting. Phosphorus was evaluated both thermodynamically and experimentally. It was found that Al, B, Ca, Ce, Cr, La, Mg, Mn, Nb, Si, Sr, Ta, Ti, U, V,...

The recycling of secondary resources to close material cycle loops should reduce the consumption of natural resources and thus help to reduce the environmental impact. For recycling, it is crucial to consider not only the nickel (Ni) content in the secondary resources, such as Ni plating waste liquids and sludge, but also the impurity levels, parti...

Owing to the growing number of risk factors that can be triggered by natural and manmade disasters, management of disruption risks in supply chains has become increasingly significant. Since the market concentration of raw material suppliers is a determinant of the supply disruption risk, identification of raw materials vital in a supply chain and...

This study seeks to understand the role of primary processing, i.e. the first post-mining stage, in supply risk, by means of a case study on three critical metals (neodymium, cobalt, and platinum) in the context of Japan. Applying the ‘footprint’ concept with a multiregional input–output model, we have quantified the direct and indirect vulnerabili...

Economic growth is associated with a rapid rise in the use of natural resources within the economy, and has potential environmental impacts at local and/or global scales. In today's globalized economy, each country has indirect flows supporting its economic activities, and natural resource consumption through supply chains influences environmental...

Objective. Supply and demand trends for mineral resources are changing rapidly due to economic growth in emerging nations and technological innovation in industrialized nations. There is a wide range of direct and indirect impediments that pose potential risks to mineral resource supply chains. These factors include stoppage of mining operations du...

Substantial amounts of post-consumer scrap are exported to other regions or lost during recovery and remelting, and both export and losses pose a constraint to desires for having regionally closed material cycles. To quantify the challenges and trade-offs associated with closed-loop metal recycling, we looked at the material cycles from the perspec...

Special steel materials, including alloy steel and stainless steel, are among the most widely utilized materials in our society. Many kinds of metals other than iron accompany the special steel materials. Therefore, to achieve sustainable metals use in the steel industry, it is important to untangle the logistics of special steel materials in socie...

Economic growth has caused a rapid rise in the use of metals and minerals. In addition, the world's population is projected to rapidly increase, with increases concentrated in Asia and Africa. Asia has become the largest global user of natural resources, and established systems of production and consumption are tailored to the current high levels o...

https://journalofeconomicstructures.springeropen.com/articles/10.1186/s40008-016-0060-9

This chapter presents chemical thermodynamic analysis on the distribution of elements in metal, slag, and gas during metallurgical processing to discuss the recycling and dissipation of metals. This study shows the thermodynamic features of various elements in the pyrometallurgical process, and the results of the present work can give an answer to...

The concept of total material requirement (TMR) is introduced in this study in order to quantify the recyclability of scrap steel from an end-of-life (EoL) vehicle. The specific TMRs for the recycling of scrap steels (urban ore TMR, UO-TMR) from the EoL vehicle are estimated for four cases: conventional press-method, shredder and separation method,...

Cobalt and nickel are high-value commodity metals and are mostly used in the form of highly alloyed materials. The alloying elements used may cause contamination problems during recycling. To ensure maximum resource efficiency, an understanding of the removability of these alloying elements and the controllability of some of the primary alloying el...

Purpose The area of land transformed by the mining of mineral resources greatly varies depending on the type of mineral deposit and mining methods used. Existing factors for the land area transformed per unit of ore mined (land transformation factor) only consider differences in mining methods. In this study, key parameters impacting the area of la...

Economic growth is associated with a rapid rise in the use of natural resources, and has potential environmental impacts at local and/or global scales. Possible options to control environmental impacts associated with consumption of natural resources include the introduction of easier way to identify the consumption of natural resources and the ass...

A stable supply of alloy elements is essential for steel production, and strategic management of alloy elements is important not only for the steel industry, but for every manufacturing industry However, in the current recycling system, steel scrap is mainly used as a source of iron. When scrap contains large amounts of alloy elements, they were re...

Due to the impact of increasing global demand for high-grade steel for a variety of applications at a time when high grade iron ore reserves are becoming depleted, the removal of impurities, and especially phosphorus, has become essential. Demand in the rapidly growing car industry, in particular, is increasing pressure on steelmakers to provide hi...

There has been a sharp increase in the production of automobiles over the past decade. In 2010, one billion automobiles were in circulation worldwide. The automobile industry is one of the largest metals consumers and plays an important role in their sustainable use. Steel materials, including alloy steels that contain alloying elements (AEs) such...

Meeting the 2-degree global warming target requires wide adoption of low-carbon energy technologies. Many such technologies rely on the use of precious metals, however, increasing the dependence of national economies on these resources. Among such metals, those with supply security concerns are referred to as critical metals. Using the Policy Poten...

The BACI trade statistics for 2005 were analyzed to determine the dependency of Asian countries on phosphorus, in particular for phosphorus ore, yellow phosphorus, chemicals, and fertilizers. The data revealed a complex set of patterns, with some countries relying heavily on just one or two countries to meet their commodity needs, and others drawin...

The removability of impurities during the aluminum remelting process by oxidation was previously investigated by our research group. In the present work, alternative impurity removal with chlorination has been evaluated by thermodynamic analysis. For 43 different elements, equilibrium distribution ratios among metal, chloride flux and oxide slag ph...

In this work, a dynamic material flow analysis (MFA) was conducted to estimate the global flow and in-use stock of steel for 4 machines (engineering and construction equipment, agricultural machinery, fans and pumps, and conveyance machines) in 42 countries until 2050. Concerning 3 machines (engineering and construction equipment, fans and pumps, a...

In this study, the concept of total material requirement (TMR) has been introduced to quantify the recyclability of scrap steel from end-oflife (EoL) vehicle. The TMRs for the recycling of scrap steels (urban ore TMR, UO-TMR) from the EoL vehicle have been estimated for four cases; conventional press-method, shredder and separation method, addition...

Synopsis : Various activities performed by the ISIJ social engineering division from 1995 to present is briefly summarized focusing on its contribution to environmental researches in steel science and engineering. Totally 10 forums including the young scientist forum and 8 research-projects in this division made extremely fruitful works. From 2010,...

Over the last decade, regulations regarding end-of-life vehicle (ELV) recycling have been introduced in many countries, leading to an increased recycling rate of ELVs. However, steel scrap from ELVs is recycled as a secondary iron source in the steelmaking process with rare consideration of alloying elements loss. Consequently, dissipation to slag...

Various alloying elements are used in vehicle manufacture to reduce environmental impacts and advance technology. After being used in human economic activities, end-of-life vehicles (ELVs) return to the steel industry as scrap containing rare metals and are subjected to the electric arc furnace process. However, at present, these steel scraps are r...