You may have seen the appalling video of a turtle with plastic straw being pulled from nose? How about the video of the ocean covered with plastic bottles and bags? People should be shocked and speechless at these images.

Concerns on marine litter, in particular plastic litter, appear to have recently emerged. However, in Leader’s Declaration in June 2015, solving this issue was included as the Group of seven (G7)’s action plan for marine litter. This declaration stated that “Recognize that prevention is key to long-term success in addressing and combating marine litter and that industries and consumers have an important role to play in reducing waste.” This means the G7 shares a common belief that marine litter should be considered as an urgent global issue. Another report from Ellen Macarthur Foundation said that the discarded plastic litter to the ocean reaches at least 8 million tons a year. If we take no action, the quantity of those litter will overtake the quantity of fish.

Where does marine litter come from? Even in Japan, there is litter which is supposed to be throw in a garbage bin not only in ocean but also in rivers, on mountains, public parks, and streets. The main causes are littering or illegal dumping. Movements such as using paper straws and at stores rather than plastic ones have started. However, even if all plastic products are switched to other material, litter in the environment will not decrease without stopping littering and illegal dumping. Only the materials change but not the habit. The fact is that the reason driving switching plastics to other materials or using shopping bags is to reduce the total amount of plastic products that are difficult to recycle (Figure 1).

Actions against environmental destruction and for recycling are becoming stricter worldwide. In Japan, Containers and Packaging Recycling Law was enforced in 2000 for plastic materials. Our society is shifting from mass consumption to circulatory with 3R (Recycle, Reuse, and Reduce). This idea has started staying in our daily lives, and we are reducing litter not only containers and packaging but also others.

The trigger of the legislation for Containers and Packaging Recycling Law was full landfill, which means its consumed lifespan. According to the Annual Report on the Environment in Japan from the Ministry of Environment, the lifespan of landfills is 20.5 years for non-industrial wastes and 16.6 years for industrial wastes. Using litter as a resource is an attempt, to prolong the lifespan of landfills through continuous recycling and reducing the amount of litter to zero (Figure 1). At the plastic resources recycling strategy meeting of the Ministry of the Environment subcommittee in October 2018, action items with a numerical target of using plastic litter as resources was submitted to collaborating governments and institutions.

Today, the era requires resource circulation considering the entire life cycle, including recovery options especially for disposable packaging that are distributed in large amounts through multiple routes. For example, quality and logistics management are changing to easily recycled designed package or installing IoT (Internet of Things) or AI (Artificial Intelligence) to place customized code labels on products. This could help to reduce not only litter but also food loss.

However, stopping littering into the environment is insufficient because litter is already in oceans, rivers, mountains, pounds, parks, and cities. We need to clean up the environment. Volunteer works at event sites to pick up garbage impress many people but removing all marine litter in the ocean is impossible. Actions have already grown to national scale and the Ministry of the Environment coastal drifters allocated budgets of 400 million yen for FY2017 and supplementary 2.7 billion yen for FY2016. However, litter remains in the ocean and is washed ashore every single day even from foreign countries. To solve this problem, global cooperation is inevitable.

　Marine litter adversely influences not only the ocean itself but also marine life. Specifically, the adverse influence of accidental eating of the marine ecosystem has become new global concern.

Harmful substances are adsorbed into micro-plastics floating on the ocean. Those harmful substances are eaten by and absorbed by fish, which humans eat (Figure 2). Therefore, finding health problems related with polluted micro plastics is possible. This is a similar mechanism to the harmful substances adsorbed due to PM2.5 or China’s dust storm reaching Japan.

Today, there are two separate discussions. One is microbeads used for scrub cosmetics and they are particulates from their beginning. Another is micro-plastics and they are degraded container and packaging by UV light or other factors. In Japan, it is taken different actions. For example, the Japan Cosmetic Industry Association started self-limitation of using microbeads since March 2016.

Discussions have already begun for micro-plastics unintentionally caused on land such as tires, shoes, fibers, paints, or artificial grass. The working standards for microplastics development were founded within ISO TC61/SC14 (Environmental Aspects) in 2017. This inclusion in ISO means that the discussion is becoming more serious in terms of international standards.

The raw material of plastics is petroleum, which is also the raw material of organic chemical products such as medicines that we need in our lives. Everything, except metals, is organic material based on carbon (C).

We learn the periodic table of element in high school and of compounds combined from several elements. Collecting elements is important when production. We call their material roots as resource.

Petroleum can generate carbon dioxide (CO₂) that is one of greenhouse gases when it burns.　In addition, petroleum itself is a depletable resource, which reports state we are running out of in the 21st century if consumption remains at the present rate. The Agency of Natural Resources and Energy reported in their annual FY2018 (Energy White Paper 2018) that calculating oil production in 2016, the ratio of reserves to production of petroleum is 50.6 years.

Greenhouse effect can be avoided if CO₂ would not be discharged in the atmosphere.　At the same time, a system to apply CO₂ as a future resource of carbon for fossil fuels is developed and called Carbon Dioxide Capture and Storage (CCS). Building CCS beside facilities that generate CO₂, such as thermal and steel plants (Figure 3), has been considered. In addition, plastics and synthesis of organic chemical products made from CO₂ has already been studied.

Moreover, in the energy industry, not only petroleum but also fossil fuels such as coals and natural gases are used carefully. Rather than these sources, energy resource is shifting to green power such as solar, wind, geothermal heat, and bio fuel.

At the 21st Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21), the Paris agreement was adopted on December 2015. Its central aim is “to strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels.” This aim is difficult to achieve with only zero emission that absorbs CO₂ with the same amount of discharged CO₂. Rather, negative emission is needed to reduce total amount of CO₂ by capturing it in the atmosphere and planting greenery to absorb more CO₂.

The movement to shift to bioplastics made from renewable resource (nondepletable resource) such as bio-ethanol is accelerating (Figure 4). Bioplastics can help reduce deportable resources and plants absorb CO₂ while growing. Products of bio-polyethylene (Bio-PE) and bio-polyethylene terephthalate (Bio-PET) are already available in the market.

Among these bioplastics is poly-lactic acid, which is biodegradability. These plastics are gradually degraded into CO₂ and H₂O, which helps reduce litter and prolong the lifespan of landfills. However, bioplastics do not degrade when merely placed into soil because of specific conditions to activate their biodegradability. In European nations, with the aim to inform society, clarifying the definition of biodegradable plastic was suggested. In a European Strategy for Plastics in a Circular Economy developed on January 2018, labeling was also suggested to separate garbage collection. In addition, biodegradability is related to its chemical structure of polymer compounds, not its raw material. In fact, PE and PET made from plant-based raw materials are not biodegradable.

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As described in this article, plastics and environmental issues are interlaced with multiple factors similar to a challenging multiple simultaneous equation. In general, this material is often discussed as “plastics”, but each industry differs in its usage, length of use, and mean of recycling. In addition, we have different social system and lifestyle between Japan and other nations, but to cooperation with each other is inevitable.

We, the Meiji University Center for Polymer Science, aim to achieve the ultimate society of never discharging any artificial products into the environment for the next generations of people on earth. In this society, every artificial product is collected and recycled again and again. At the same time, we take actions to collect the litter that has already been discharged and place them back into the source circulation. We would be honored if you cooperate with our efforts.

January 2, 2020 – Hitoshi Sugiyama, translator

This is a translation from the Japanese original article written by Kazukiyo Nagai, which was published on February 26, 2019.