Promote plastic sorting in floating villages to reduce the generation of marine plastics
Sustainability of Resources, Graduate School of Environmental and Life Science Takeshi Fujiwara
Professor, Graduate School of Environmental and Life Science, Okayama University
Deputy director, Low Carbon and waste Recycling Research Center (Waste Management Research Center)
Specialty: Environmental systems engineering, waste engineering, waste management
（Photo: He is on the far left.）
Various studies to build a sustainable goods circulation system
Project training at JICA Cambodia office (2018)
――First of all, could you tell us about the kind of research you are doing in the field of waste resource recycling, your specialty?
There are three recent research themes: the first is "Considering a Sustainable Recycling-Oriented Society," the second is "Biomass Waste Recycling," and the third is "Measures for Disaster Waste”.
The first research theme, "Considering a Sustainable Recycling-Oriented Society," includes the overseas project we are working on this time, which will be explained later. In addition to the overseas project, we are also researching how to create a recycling-oriented society in Okayama City and Okayama Prefecture. We are always dealing with materials and objects. The flow of materials is called a recycling-oriented society, in which materials do not end up in use, but circulate in society and are properly returned to products again. If something is produced in Okayama City, it is circulated in Okayama City, and if it is produced in Okayama Prefecture, it is circulated in Okayama Prefecture, and so on. Just like the term "local production for local consumption" is used for food, we are trying to create a closed system in which products are recycled in a certain region after they are used in that region. We are conducting research to grasp the flow of materials and mathematically plan how to create a better circulation.
――Please tell us about your second research theme, "Biomass Waste Recycling.
Recently, there have been policies to use electric cars and solar panels, but I think it would be better to circulate more renewable biomass that comes from plants and animals around us. What we are working on is circulating within the campus of Okayama University. It is a very large campus, so there are a lot of plants and trees, and there are a lot of fallen leaves. The cafeteria produces leftover food, there are cows that defecate on the farm, and horses are kept at the riding club. Although it is one campus, various types of biomass are produced depending on the season and timing. For example, fallen leaves come out in the winter, grass in the summer, and leftover food during the semester, which decreases dramatically during vacations. Animal droppings also change depending on the number of animals you have. In addition to absorbing these changes, energy called methane gas is produced from the biomass. We also make fertilizer from the waste, called compost, and return it to the farm. For my part, I would like to make flowers and plant them in various places. We don't have to buy flowers from outside, we can just plant the flowers we grow inside the university, and we can create a closed world. Since we are at a university, this research is about coming up with a system to circulate the large amount of waste that comes out of the university.
――Please tell us about the third theme, "Measures for Disaster Waste".
Have you ever heard of hazard maps? For example, every municipality has hazard maps that show how much this area will sink in the event of a flood. Based on the hazard map, we can calculate in advance how much garbage will be generated if a disaster occurs in this area. If we can calculate in advance, it will be easier to create countermeasures. For example, we can make a plan based on the predictions of how many trucks will be needed to handle the garbage generated by a disaster, or how much area will be needed for temporary storage of the garbage. The problem is that when a catastrophe of a magnitude never experienced before strikes, municipalities are confused and do not know what to do. In July 2018, a major flood disaster occurred in Mabi Town, Kurashiki City, and that is exactly what happened in Kurashiki City. When a flood disaster like that happens in a district where disasters do not usually happen, city officials get panicked and do not know what to do. Therefore, in order to avoid problems in the event of a disaster, we predict how much disaster waste will be generated based on hazard maps, and make plans in advance to dispose of it.
The ocean pollution and its impact on ecosystems caused by marine plastic waste have become a global environmental issue
Scattering of plastic waste
――Thank you very much. Now I would like to talk about your overseas projects. You have been working on a project to eliminate marine plastic waste by involving local residents in the sorting of plastic waste in a floating community on the largest lake in Asia. Could you tell us about the current status of the marine plastic problem?
It is reported that 8 million tons of plastic are currently flowing into the Pacific Ocean and other oceans every year, and that by 2050 the amount of plastic flowing into the oceans will exceed the weight of all fish alive at that time. The good thing about plastic is that it is durable, but in the environment, it is known to be persistent, causing damage to the marine ecosystem, which is now a global environmental issue. How durable do you think plastic is? For example, how many years does it take for a plastic bottle to completely decompose?
――About 10 years, I think.
It is reported to be 450 years. Diapers are also made of plastic and take about the same number of years as plastic bottles. Fishing line and nets take 600 years to completely decompose, and a heat-retaining plastic called a styrofoam container takes 50 years. The most commonly discarded plastics in the ocean are leisure-related plastics and plastics from the fishing industry. Even people who don't usually dump illegally throw away containers there when they go on leisure trips, or when they find holes in nets for catching fish, they throw them away and go home. This means that we cannot take responsibility for the plastic we have now or for the plastic we throw away. We have to think about how to deal with plastic in the future, being aware that we have to take care of it and manage it for generations to come.
――I have heard stories of fish eating plastic and then humans eating the fish and the plastic accumulating in the human body.
Yes, that's right. But fish can't eat something that big, so what you just mentioned is a small plastic called microplastic.
There are two types of microplastics: one is originally large plastic that has broken up and become finer and smaller over time. Large plastics such as plastic bottle caps and plastic bags have deteriorated and become smaller, and this can be prevented by not allowing plastic waste to flow into the ocean.
But the other type of microplastic is the fine plastic that is put into products from the start. For example, we all brush our teeth, and some toothpaste contains tiny plastic abrasives. When you rinse it out in your mouth and throw it down the drain, the particles go down the river into the ocean, where they are eaten by small fish. There are also very small plastics in detergents, cosmetics, and other everyday products. After use, they go to sewage treatment plants, but because of their small size, they pass through the treatment and end up in the ocean along with the purified water.
When we think of plastic, we inevitably think of plastic bottles and plastic bags, but it is the small plastics that are artificially put into products that are of great concern today. This is the plastic that you mentioned earlier that accumulates in humans. Studies have shown that these plastic particles have already been ingested by the human body, but they are not absorbed, so they are discharged. In recent years, research has been conducted to determine what effects microplastics have when they enter the human body, for example, whether the organics and metals contained in plastics affect the human body. So far, there are no findings that microplastics cause health problems, but if they do in the future, it would be a big problem.
――I was surprised because I didn't know there was plastic in toothpaste and detergent.
Thus, the problem of marine plastic is caused by various factors such as microplastic spills and illegal dumping of plastic waste. In fact, China and Southeast Asia are the largest emitters of marine plastic waste. China has a large population, which results in a large amount of total emissions. Southeast Asia is a major source of plastic waste compared to other developed countries because they do not have adequate waste disposal systems in place after using plastic.
Currently, as a countermeasure against marine plastic litter, plastic products are being replaced with paper products, for example, and biodegradable plastics, which are degradable by microorganisms, are being developed. However, there is already a lot of plastic in circulation, and a lot of plastic has been produced in the past. Currently, there is a large amount of plastic left in landfills around the world. This is because organic matter decomposes over time, but plastic remains until the end. It is quite possible that rain will fall there and the plastic will flow into rivers and pollute the oceans. So even if we change the type of plastic now, there is still a possibility that some of the plastic that was discarded in the past will still be found. So I think it is important not to dump plastic into the ocean and not to turn it into marine plastic waste.
So we are trying to start recycling plastic in places where discarded plastic is likely to become marine plastic. In particular, we want to do something about the fact that plastic is often dumped into rivers and oceans in developing countries in Southeast Asia, so we have decided to target the Kingdom of Cambodia to address the sources of marine plastic waste.
How to make people in developing countries who do not have the habit of separating garbage into separate categories
Garbage at the final disposal site in Cambodia (Phnom Penh)
――Why are people in Southeast Asia and other developing countries dumping plastic into rivers and oceans?
In some developing countries, there is no service to collect garbage, regardless of whether it is plastic or not, to begin with. Only developed countries have a system like Japan's where the local government collects garbage, and in other countries, only those who have paid for garbage disposal are allowed to throw it away. This means that low-income people cannot have their garbage collected, so illegal dumping is commonplace, with people throwing garbage around or into rivers and the ocean. So, if we want to reduce ocean plastic, we have to fundamentally reform waste disposal.
You all think that garbage is burned in incinerators, but Japan is the only country in the world where garbage is burned normally. There are very few countries where municipalities always have incineration facilities. We pay high taxes to have our garbage disposed of and maintain a comfortable living environment. In other countries, however, they cannot spend that much money on garbage collection, so the collection service is basically provided to those who pay for it, and it is not possible to build very expensive infrastructure such as incineration facilities. There are only a few countries where incineration of garbage will be the basic method in the near future.
Nevertheless, if they are throwing garbage away, it will not stop plastic from becoming marine debris. Therefore, I think we should start collecting plastic alone as soon as possible in places where it is likely to become marine plastic. In places that do not border rivers, even if garbage is thrown away, it is unlikely to flow into the ocean, but after all, if you live near a river, it is quite possible for it to flow in when it rains. In the area that the project is targeting, there are wet and dry seasons, and during the rainy season, the volume of water increases and all the garbage that was scattered around the area until then is washed downstream. Therefore, urgent measures are needed, and if the government does not have the money to take action, I believe that the residents must do their own sorting and collection of plastic waste.
However, even if we talk about separating plastics, we need to consider what to do with the separated plastics. In developing countries, NGOs and other organizations sometimes cooperate with local sorting efforts, but there are stories of people who are unable to do anything with the plastic they collect and end up taking it to landfills. There are cases where people end up only raising awareness of the need for sorting. So if we are going to collect plastics, we need to turn them into resources. In Japan, policies encourage a recycling-oriented society, in which paper, metals, plastics, etc. are recycled back into raw materials, but developing countries do not have such a system.
――How are you going to make the separate collection of plastic waste take root among people who are not in the habit of sorting?
The idea is to help them earn an income from plastic recycling. In Japan, people are educated in various aspects of garbage separation, so if you ask them to separate garbage, they will do it. However, even if you tell people who do not have the habit of separating garbage at all to "start separating garbage today," it is difficult to get them to do so. Therefore, we are considering a way to provide incentives to those who cooperate in sorting. This is a system in which plastic is collected and converted into resources, where some income is generated, and incentives such as electricity, drinking water, and other daily necessities are distributed to those who cooperate in sorting. In order for this to take root, I believe that it is important to trigger people to say, "I will cooperate because it will be good for money," and once this takes root to some extent, people will naturally develop the habit of sorting.
Also, in order to go into these districts and make waste separation take root, we must not only create a system, but we must first educate the people of that village. This is called educational enlightenment, and it aims to help villagers understand that the plastic they use in their daily lives is linked to marine plastic pollution. They need to understand that they need to sort their own garbage in order to improve the world's environment. But since this understanding is not related to their own interests, we need to find a way to connect the two. We Japanese are also taking measures because we are told, "This is the time we live in, and if we do not do this, we will not be able to prevent global warming, so let's do this," but I think some people are wondering why we have to do it. Some are doing it because everyone else is doing it somehow, and others are doing it with full understanding. But it is impossible to sort waste or take measures against global warming without any knowledge or understanding. If we explain the situation carefully and ask for understanding, and if people still don't do it, we have no choice, but if there are people in the village who have empathy for us, they will cooperate with us in sorting waste.
To reduce plastic waste, each villager must be aware of the problem of the habit of dumping waste in the lake
Scenery of the floating villages
――What kind of region is Tonle Sap Lake in the research area?
Tonle Sap Lake is the largest lake in Southeast Asia, 24 times the size of Lake Biwa during the rainy season and four times the size of Lake Biwa during the dry season. Because of the expanse of the lake in this area, building houses on land makes it difficult for fishermen to move around. The people's job is to catch fish and sell them, so many of them live on flat boats with roofs floating on the lake. People who live on their boats gather together and build towns by attaching their boats to each other, so villages have been established in various places on the large lake. Among them are stores, elementary schools, public facilities, and churches, all built on boats. The boats for transportation use gasoline. Because of the location, there is no electricity in the area; it is powered by batteries. Food and water come in from the land, so they live close to the land, and when the water level increases and the lake widens, they move their entire village accordingly.
The water in the lake here is muddy, so drinking water is mostly bottled water. Local Cambodian and some foreign food items are sold, and people buy food in plastic bags as normal. Although the standard of living is low, they have no choice but to use plastic in their daily lives, especially for food, for hygienic reasons. Then, although there is plastic that comes in, the garbage is not processed (some of the plastic is burned in the field), so there is no plastic to go out. They are dumped into the lake. Food is fine because it decomposes by microorganisms or becomes food for fish and disappears, but plastic is floating or sinking as it is for a long time. During the rainy season, the water level increases and the discarded plastics flow downstream. The plastic then flows downstream to join the Mekong River to form the wider Mekong River, from where it flows into the ocean. The villagers are aware that the river will properly clean the area because the garbage is washed away during the rainy season and the garbage is gone during the dry season.
――Do they flush their excrement into the lake as well?
Yes, they do. The toilets in the houses on the boats have only a hole in them, and the water from the lake is kept in a jar, scooped out with a ladle, and poured into the lake. So human feces and urine, along with leftover food and kitchen garbage, become food for fish and plankton. In the past, this was not a problem because microorganisms would eventually break it down as part of nature's purification process. In fact, the number of fish increased in this way, and the balance between nature and human life was maintained. However, the creation of plastic by mankind has created garbage that does not disappear. When catching fish, discarded plastic can get caught in the water, and when boating, it can get caught in the propeller. Some villagers are concerned about environmental problems in the area because their daily lives are somewhat affected. There is a need to change the villagers' awareness because they are not aware of the problem of discarding plastic.
The JICA Partner Project "Participatory plastic pollution control with residents of floating villages on Tonle Sap Lake in Cambodia" is targeting this area to somehow make the people there understand the plastic problem and voluntarily sort plastic.
Implementing a self-sustaining system for plastic waste sorting, collection, and recycling in floating villages
Explanation of the project, hearing, and exchange of opinions at a meeting of village commune leaders
――Please describe your project in detail.
If we were going to carry out such a project, we had to get the approval of the local people in advance. Therefore, during our first visit in April 2022, we went to the JICA office in the target country to ask them to prepare the environment for our activities, and we visited the site to talk with the village representatives. We raised the issue with everyone, explained what we were trying to do, and obtained permission for our activities. We also interviewed women who catch fish about plastic dumping, and we interviewed junk buyers, people who now collect and sell empty cans, about where they collect them and how much they sell them for.
In September 2022, we visited for the second time and conducted a hearing survey and a composition survey of garbage in order to clarify the actual situation of plastics. As part of the hearing survey, we asked each household whether they have "knowledge" of plastic, "awareness" that it leads to environmental problems, and "consciousness" to cooperate in sorting. We also need to know how much plastic is actually generated and what kind of plastic is produced, so we conducted a survey on the composition of garbage. In Japan, we receive garbage from ordinary households and examine the food scraps, plastics, metals, etc. in detail. We did the same thing in Cambodia. However, since we were targeting plastics, we classified only plastics. We prepared two bags for cooperating households and asked them to put plastic in the white bag and other garbage in the black bag. We asked them to collect the plastic and wanted to see how well they could sort it. When we opened the white bags we collected, we sometimes found empty cans in them.
We are planning to create an educational manual to carefully explain about sorting. We would also like to make educational materials for children using cartoons and other materials. If there are people in the university who are good at or like drawing, We would like them to participate. In addition, we will gather a team of people from the village who want to promote sorting and sorting, and invite them to Okayama City. We will ask them to visit a factory to see how sorting is done in Japan and to learn how the sorted items are recycled. The duration of the training will be about one week, and we will give them guidance on sorting and learn about techniques. We hope that people from this team will take the lead in implementing sorting in the village. The next visit will be in December, so we are planning to hold an educational event. Once the system is somewhat complete, we will gather the villagers and talk to them about plastic knowledge, education, and the sorting system, and tell them that we will pick up their garbage twice a week, so please keep your garbage separate, and if they cooperate, it will be slightly better for them. Then We will try to enforce the sorting system all together. Since the period is short, we will first try it, find out how much cooperation we can get and how much we can collect, and then decide whether we can do it or not. We will also conduct a parallel investigation of routes for recycling. If we can collect a large amount of plastic other than bottles, there may be companies that will buy it. Since we can know the amount of plastic that can be collected through this survey, we would like to calculate how much it will cost and actually sell it to return the income to the villagers.
Hearings with recycled materials recovery businesses (junk buyers)
――Thank you. I wonder why no villagers collect and sell plastic, but some collect empty cans!
This is because empty cans are very easy to recycle.Whether iron or aluminum, it is easy to melt a metal by applying heat to it and turn it into a lump of metal called an ingot. Iron and aluminum can be separated by magnets, so they are melted down and used as raw materials in many countries around the world. Therefore, there are people who collect aluminum and steel cans and sell them for money. However, recycling of plastics is not widespread enough. It takes some technology to convert plastic bottles into other products, and in Cambodia, this has not been done yet. In Japan, the cutter shirts, shirts, and suits we wear can be made from plastic bottles, and the material can be melted down to fiber, which is then knitted back into clothing. High technology is required to recycle them into high quality products, but it is possible locally if the technology is simply to melt them down and use molds for molding and processing. However, since the prices of the products are low, they do not generate good income from waste collection.
――Are there facilities in Cambodia to process plastics after sorting?
There are none! At the moment, there are no companies that recycle, so the plastic collected in Cambodia is taken to neighboring Thailand and Vietnam to be sold, or sold to traders from those countries who come to buy it. However, many fees are charged when garbage crosses the border. Garbage is not really supposed to be moved from one country to another, so people have to do all kinds of tricks at the customs offices between countries and pay to get it through. That is why the purchase price of garbage is inevitably lower. Plastic bottles are just barely profitable, but I hear that they do not do this for other plastics because there is almost no money to be made from collecting them.
Japanese companies are also trying to expand their recycling technology overseas, and we are in contact with them as well. The world of garbage collection has a slightly dark side, with an implicit vested interest in collecting and recycling garbage, and if someone collects garbage individually within the territory where someone else collects it, various complaints arise. Recycling business overseas is not as simple as just going there and building a factory, but it is necessary to start by acquiring the rights to operate the business there. But if we are going to sort garbage, ideally we should have a recycling company nearby with processing facilities, so that we don't have to take our garbage to a neighboring country. We will continue to look for places nearby that recycle.
Garbage composition survey with local teachers (Royal University of Phnom Penh) (2022)
I hope this project's system can spread as a reference for floating villages around the world and contribute to environmental improvement
――It will be a very long road for the recycling system to take root....
Research can be done in one's own room, but implementing research-level system into society can be a challenge. Based on data collected in the field, the university conducts studies to determine how much plastic can be collected and sold at what price per unit. However, this is only for the system design, and when it comes time to have the system actually used, I realized that efforts are centered on education and training, interviews and negotiations with local suppliers, and other aspects that are separate from the usual research, and I realized how difficult overseas cooperation is. It is more engineering than science, and even in engineering, there is a large social component. I think there is a large social science component when creating a system to run in society. I think we have a long way to go before a sorting system is implemented throughout the village, which would visibly reduce the amount of plastic being thrown away.
――I realized once again that it takes a lot of time and effort to improve environmental issues.
I believe that the environmental field is such a field. For example, biodegradable plastics are developed through corporate research and development, but society recognizes them and the government creates policies and subsidy programs to encourage their widespread use. This will lead to citizens' action, but it will take many people and a long time before it becomes a matter of course. I don't think people will move if the government simply makes a law and says, "Let's do this. In Japan, government officials hold lectures and campaigns at various places to explain the importance of waste separation to citizens on a regular basis. I believe that only through such efforts can the environment be slowly improved.
We are trying to practice plastic sorting in foreign countries, albeit on a small scale, and hope to make a successful case study. If a recycling system in which all villagers participate can be established, the example will spread to nearby villages. There are many villages in the world that live on water, like Tonle Sap Lake, so I hope that examples will spread to those areas as well, leading to environmental improvement.
――Prof. Fujiwara, thank you very much for your many talks!
Cambodia Research Tonle Sap Lake Field Study Project Practicum (2018)