[Special Feature: Toward a Circular Economy and Society] Yutaka Kameda: Challenges for a Circular Society Seen from Global Microplastic Pollution

The problem of plastic emissions into the environment is considered by many countries to be an urgent issue to be solved, similar to the problem of climate change caused by global warming, and intergovernmental negotiations aimed at concluding an international treaty have begun. However, it is ironic that plastics were originally celebrated socially as a magic material that brought about "Throwaway Living," as featured in the 1955 American magazine LIFE, and the current situation is the result of that lifestyle having steadily spread throughout the world.

However, it is by no means rare in history for former magic materials or chemical substances (such as dioxins, Polychlorinated Biphenyl (PCB), Perfluorooctanoic acid (PFOA), etc.) to have their high risks to humans and wildlife clarified decades later, leading to restrictions on their use. Yet, it is becoming clear that conventional chemical substance regulations and measures are insufficient for the current plastic problem because it has different pollutant characteristics and social backgrounds compared to past chemical substances. Below, from the perspective of a scientist who serves on committees for relevant ministries while also conducting surveys, analysis, and shaking test tubes at the front lines, I would like to consider the new challenges for a circular society regarding microplastics that are becoming visible.

Currently, the plastic problem in Japan centers on plastic waste such as shopping bags and PET bottles. However, plastics on Earth are distinguished by experts—though definitions vary slightly—by size into macroplastics (25 mm or more), mesoplastics (5 mm to less than 25 mm), microplastics (1 μm to less than 5 mm), and nanoplastics (less than 1 μm), and are considered distinct entities based on their toxicity and environmental behavior. The center of discussions regarding circular societies in Japan today is "macro, meso, and microplastics of 0.3 mm or larger." However, in the EU, where research on plastic toxicity in aquatic environments such as oceans is about 15 years ahead of Japan, it is considered that microplastics of several tens to 1 μm are the ones that should be most concerned regarding toxicity and risk. In other words, there is a large gap between the thinking of the EU, which is at the forefront of global microplastic regulation, and that of our country.

I feel that the cause of this gap lies in a way of thinking unique to the Japanese administration. That is, because Japan has the results of over 10 years of surveys on microplastics of 0.3 mm or larger in the waters around Japan, there is a "conservative mindset" that suggests there is no need to investigate fine microplastics now. Furthermore, another cause may be the "Japanese way of thinking of covering up something unpleasant (something inconvenient for administration or the economy) despite the latest scientific results," by not incorporating information from the EU, where the dangers of fine microplastics have been a concern since that time. As a result, a vision for a circular society regarding large-scale plastics developed in Japan.

Consequently, as a result of investing budgets in the unknown and accumulating research results, the EU derived the truth that microplastics finer than 0.3 mm have a higher ecological risk, and is aiming for a vision of a circular society based on that. Recently, they have taken a leading position in the world at a level that will significantly transform current supply chains, such as considering EU directives regarding the manufacture and use of microplastics. For Japan to propose a circular society to the world in the future, it will likely need external proactiveness and steady effort to understand a world with different concepts without hesitation, evaluate them scientifically, and then hybridize them.

The current scientific capability of environmental science in Japan and its system of cooperation with the administration may not be able to respond to global environmental problems that exhibit chronic toxicity or non-linear behavior, such as the plastic problem and global warming. A typical example of this can be seen in the response to the COVID-19 pandemic, which seems to apply to the microplastic problem to an almost amusing degree.

For example, at the beginning of the COVID-19 pandemic, rapid scientific analysis of the virus (genome analysis, etc.) was carried out overseas, and the development of PCR technology for tracking the number of infected people and determination technology using immune antibody reactions was actively implemented. Japan showed similar movements but did not lead the world; rather, only the drawbacks such as immune antibody reactions and false positives in PCR were discussed, and it took a long time to start comprehensive surveys of the number of infected people. Furthermore, while PCR testing was reported as "advanced technology" in Japan, from my perspective as someone with analysis experience, it is merely a technique that an undergraduate student can master in one month. I felt the horror of Japan, where citizens have low scientific literacy and do not doubt the mass media, seeing such mistakes pass through unchallenged.

In fact, the survey and analysis technology for microplastics in Japan is in exactly the same situation. That is, sufficient microplastic surveys still cannot be conducted in Japan, and furthermore, there are only a few scientists in Japan, including myself, who can easily analyze sizes of several tens of μm. Under such circumstances, is it possible to formulate correct policies? Incidentally, around 2018, when microplastic research first gained serious attention in Japan, the general analytical method was to separate suspended solids in seawater by density using a separating funnel or the like, and then have an analyst pick up things thought to be plastic one by one with tweezers to identify the material (Figure 1). This method can clearly only measure things of a size that can be picked up with tweezers, about 1 mm. Also, since it is a task of picking up things smaller than a grain of rice, the analytical precision is low, and it wastes labor and time. Sadly, this method is still the mainstream in Japan today, and not all microplastics are being surveyed or understood. And only in the last few years has there been a struggle to quickly build a system capable of analyzing the fine microplastics that the EU emphasizes.

Fortunately, because I had been fixated on fine microplastics since that time, I was considering the acquisition of expensive equipment that could be expected to analyze them. However, there were many cold opinions such as "I acknowledge the importance of fine microplastics, but it is technically difficult" and "Is the value of the development effort worth the expensive equipment (15 million yen)? I cannot find value in research on fine microplastics with low analytical possibility," and it was extremely difficult to get adopted for KAKENHI (Grants-in-Aid for Scientific Research) and the like. This lack of social challenging spirit and emphasis on short-sighted efficiency is highly likely what caused the current delay in Japan's microplastic policy.

Fortunately, I did not give up and presented my research plan to the upper management of an American manufacturer, negotiated directly for a rental of the equipment, and further petitioned the university president for its purchase, eventually managing to obtain the equipment. In the end, this persistence paid off; I succeeded in developing an automated analysis method for fine microplastics in 2020 and publishing a paper on it in 2021, and I am now one of the few researchers in the world capable of routine measurement of fine microplastics.

Generally, environmental problems are caused by substances whose physical properties and ecological impacts are unknown. The first step toward a solution is understanding the current situation through analytical technology, surveys, and analysis. No environmental problem can be solved without this. Therefore, as my case this time applies, it is important to build a proactive basic research system. Japan should possess the foresight, strategy, and expertise to understand and provide large-scale financial support for basic research, like the EU and the United States. Furthermore, even regarding financial support, if several tens of millions of yen were provided per person to about 10 researchers in the country for one or two years, Japanese scientists would surely succeed in developing analytical methods. How inexpensive this would be compared to the construction costs of sports facilities where large-scale events can be held.

There is also the opinion that applying overseas technology is more efficient than independent development in Japan (there is no need to be number one). However, as I felt during the development of the survey and analysis method for microplastics this time, we must not forget that the knowledge and experience gained through repeated failures until completion become the foundation for the development of the next new technologies, such as microplastics of several μm or nanoplastics.

In this way, as with the response to the COVID-19 pandemic, important elements regarding the construction of an unknown new circular society begin with the development of steady technology for understanding the current situation, its system, and the acquisition of accurate data. Only with these can strong philosophies and ideals be born, long-term visions and milestones become clear, quantitative consideration of achievement goals including uncertainty become possible, and the construction of a circular society steadily approach. In current Japan, there is a poor understanding of the importance of basic data, and policies are decided by a "voice from on high" in a state where visions are unclear and policy effects cannot be quantified. Furthermore, when unfavorable results emerge, a negative spiral occurs where the situation is settled with the catchphrase "unforeseen," like Mito Komon's seal case, without any quantitative explanation of the assumed range.

In EU policy, scenario analysis of measures considering various uncertainties is mandatory, and quantitative prediction of policy results is a matter of course. Therefore, even if results deviate significantly from predictions, quantitative investigation of the cause and new measures to correct it become objectively and scientifically possible. I am currently cooperating with the EU on international measurement technology for microplastics, and what I can say from that experience is that for Japan to build a new circular society and propose it to the EU and the world, it needs philosophies and ideals that convince them, as well as objectivity and quantifiability to make them understand.

In Japanese environmental policy, there is a history of emphasizing "participation" and "awareness" at the citizen level, but it is difficult to convince the world with this. We must not forget that what is ultimately important is the substantial effect of the policy—that is, the reduction of the environmental load and risk of plastics. For that purpose, a quantitative understanding of the current situation is important. There are still not a few local governments that "prohibit" microplastic surveys as something that stirs up anxiety among citizens; Japan, which is truly covering up something unpleasant, should look at itself once more and grow.

In the previous section, I stated Japan's challenges, but since that alone would end as a scientist's "howling in the wind," my group established a system for conducting marine surveys of microplastics led by the private sector with Nippon Yusen Kabushiki Kaisha (NYK Line) in 2020, and began the world's first global-level understanding of the current distribution of fine microplastics in the ocean.

In fact, there are many unknown points regarding the distribution of microplastic marine pollution. There are two main reasons for this. One is that because analytical methods differ for each research institution, it is impossible to compare concentrations and plastic compositions between locations at a global level. The other point is the small number of survey locations due to the high cost of marine surveys (tens of millions of yen per day). To solve these, we built a private enterprise network to collect microplastics on routes using ocean-going trade vessels of the NYK Line Group, which is proactive in marine conservation. The collected samples are automatically and rapidly measured for fine microplastics in this laboratory, and the data is released to the world. Conventionally, the main body of environmental conservation was the government, but a global-level survey where private companies took the lead as volunteers can be called a world-first historical event. An example of the results is shown in Figure 2.

This world-first survey revealed results different from our expectations. For example, the concentration distribution of microplastics in the ocean was remarkably non-uniform, ranging from 21.6 to 4660 particles/m³. In particular, sea areas affected by the Kuroshio Current, the North Atlantic Current, and the California Current had high concentrations, and the composition of microplastics changed significantly by gyre. These results suggest that movement between gyres is small and that sources and their characteristics differ by region. In other words, for marine microplastic policies, coordinated measures by multiple countries involved in each gyre are essential. This means that no matter how much the EU sphere takes the helm of the world, the far-off Kuroshio Current region needs Asian and Oceanian countries to take the lead in implementing measures, and that is precisely where Japan's leadership can be expected.

Furthermore, the creation of a new international main body that transcends the unit of the nation and the effectiveness of marine conservation through measures centered on that main body are also interesting. This is because, under current maritime law, permission is required for surveys in Exclusive Economic Zones by other countries' research institutions and for the disclosure of that data to other countries, even if it is environmental information (though plastic is marine litter). Therefore, to protect the "Seven Seas," a foundation of harmonious high-precision survey and analysis methods, funds for implementing survey measures, and sharing of survey results are essential, and a new international organization different from conventional ones is required. Therefore, we are currently contacting researchers around the world to attempt the creation of a new international organization. For global-level environmental problems such as global warming and the plastic problem, it may be acceptable to have a new organization with strong ideals and powerful execution based on scientific knowledge, rather than relying on nations or existing international organizations. This might be the clue to solving global-level environmental problems.

Above, I have stated my personal views from the standpoint of a scientist conducting research. The problem of plastic environmental pollution has permeated our lives to a level where its removal is essential, and because the sources of emissions into the environment are diverse and unknown, all industries must respond effectively and harmoniously with the final goal of reducing the total load on the environment. Furthermore, a strong and reliable helmsman to coordinate them will also be necessary. Moreover, a helmsman will be needed not just at the domestic level, but at the Asian and even global levels. And perhaps the new helmsmen for future environmental problems need not be governments or international organizations trembling unstably on the political power balance, but rather private-sector vitality or scientists who possess execution power and sufficient funds.