Emissions of anthropogenic reactive nitrogen have led to the emergence of serious threats to both humanity and the environment. A nitrogen footprint is a novel indicator that quantifies, on a consumption basis, the loss of reactive nitrogen to the environment through human activity. We describe three recently proposed methods to determine a nitrogen footprint: N-Calculator; N-Input; and N-Multi-region. N-Calculator applies a bottom-up analysis, which is based on per-capita food and energy consumption, to describe how each of a consumer’s actions impacts their nitrogen footprint. N-Input uses a top-down analysis—which is based on agricultural nitrogen inputs and the production, importing, and exporting of food—to accurately assess nitrogen flows for countries that import food from multiple foreign states. N-Multi-region employs input–output analysis using a global, multi-region input–output table that is extended to cover sectoral reactive nitrogen emissions of each country/region. This method can estimate nitrogen footprints of many countries while considering complex international supply chains and different reactive nitrogen types. We also review related research projects, and current and potential measures to decrease nitrogen footprints; these include food choices, decreasing household waste, footprint labeling（for nitrogen, carbon, and water）, institutional footprinting（for nitrogen and carbon）, and nitrogen-footprint offsetting.

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Phosphorus（P）, along with nitrogen and potassium, is one of the three major nutrients essential for plant growth and an indispensable resource for fertilizers. Mineral P ore is the essential source of the phosphorus currently used for economic purposes worldwide. According to a 2018 report from the United States Geological Survey, about 75% of total global P production takes place in three countries: China, Morocco, and the United States, and more than 70% of global economic reserves of phosphorus ore are in Morocco. P ore is used mainly as a source material for fertilizers, but there is also a large demand for industrial uses, including semiconductors, surface treatment agents, EV secondary batteries, pharmaceuticals, and processed foods. As a resource essential for food supply, phosphorus is viewed as a strategic resource in the world, and its sustainable use is a topic of ongoing discussion especially in Europe and Asia. To ensure the sustainable management and conservation of phosphorus resources, phosphorus resources should be used more efficiently by agriculture and other phosphorus-dependent industries. To this end, we need to establish economically efficient conditions to implement the full-scale recovery of unused phosphorus resources, to develop phosphorus recycling technologies, and to realize the sustainable P value chain.

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One century has passed since the establishment of the artificial nitrogen fixation process using abundant molecular nitrogen in the atmosphere. The fixed nitrogen has provided chemical fertilizers to boost food production and materials for chemical industries, which have contributed to population and economic growth of the world. This new nitrogen flow grown in the anthroposphere of the Earth system is now very huge and disturbing natural nitrogen flows in the other Earth subsystems. Therefore, a framework of nitrogen management is needed to maximize benefits and minimize threats for sustainable human nitrogen use. This article introduces activities related to an international project, Towards International Nitrogen Management System（INMS）, through the standpoint of East Asia and Japan, and states expectations of future studies in the field of industrial and LCA research.

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It is of great importance to consider strategic food production to cope with ongoing rapid increases in population. For effective mass food production, addition of fuel for heating, artificial fertilizers, and agricultural chemicals, etc. are indispensable. In order to supply these inputs, a large amount of mining activities accompanied with energy and mineral resources are required, and these are largely hidden flows from the perspective of the consumer. In this study, we have proposed a framework to quantify mining activities relevant to food production in terms of total material requirement (TMR), which has been applied to food material in Japan as a case study. Targeted food material were 41 types of domestic vegetables, 8 types of fruit, 16 types of seafood, and 5 types of livestock. Domestic and foreign livestock feed was also considered. The functional unit was set as “1 kg of food material to be shipped”. The results indicated that the specific TMR (kg-TMR/kg) for food material with similar production methods showed similar values. Generally, contributions by energy were dominant for vegetables cultivated in a greenhouse and fertilizer inputs were dominant for non-greenhouse cultivation. On the other hand, the specific TMR of livestock feed was relatively small compared to vegetables, with no major difference observable among the different feed types. The specific TMR for seafood production by set net fishing was relatively low compared to other fishing and the effects of fishing tools and energy were negligibly small, the effect of energy ascribed to fuel was dominant for other fishing types using boats. For livestock, the specific TMR for a beef cow was 5 〜 6 times as high as that for pigs or broiler hens.

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Objective. The environmental hot-spot of a product for cleaning the face and washing hair, such as face wash and shampoo is in the use stage. This is due to the fact that the amount of water or hot water required for rinsing off is significantly higher than the amount of the product contents. The contribution of these cleansing products in organizational GHG emissions is the largest among the personal care products business due to the carbon footprint of individual products and sales volume. For this reason, reduction of the environmental burden at the use stage of the cleaning products has been a big problem for personal care sector industry. Shiseido Company, Limited launched the easy-rinse foaming face wash which has the improvement on reducing the volume of rinsing water by the dispersibility of dirt into the water. In this study, we selected the easy-rinse foaming face wash as a research target, and evaluated the reduction effect on life cycle GHG emissions and water consumption compared to the paste type product or the conventional foaming product.
Result and Discussion. This study clarified that the target product reduces 1.40 kg-CO₂e and 1.96 kg-CO₂e of GHG emissions respectively, compared to the paste type one and the conventional foaming type one on the premise of a functional unit: “164 times of washing faces” with 40℃ hot water. The functional unit is defined based on the actual usage in the market. Also, on the water consumption, it can reduce 0.282 m³ and 0.404 m³ respectively throughout the product life cycle. However, in the case of under 21℃ or less of rinsing water, the GHG emissions of the target product becomes always higher than that of the paste type face wash. The use condition is affected by various factors such as consumer habits, social infrastructure, as well as the climate in the market area. When we aspire reducing the environmental burden of a product, it is important for product developer to reflect more effective option onto a product design based on detailed analysis taking the local and unique circumstances into consideration.

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