Integrated Management of Urban Environment for Sustainable Development

Rene Castro Blog, Reports November 19, 2015

By: Bangkok Unit Team

The Global Field Exercise (GFE) we had in Bangkok was fruitful while fun at the same time. It was a two-week field exercise course for the graduate students of the University of Tokyo, Asian Institute of Technology, Chulalongkorn University, Thammasat University, and Mahidol University under the Interdisciplinary Consortium on Urban Environment and Health in Asia program (UEHAS) and Global Field Exercise (GFE) of Graduate Program in Sustainability Science Global Leadership Initiative (GPSS-GLI).

During the urban transition phase from developing countries to developed countries under democratic and rapid economic growth, cities are rapidly changing in terms of living standards, social behaviour and health. During this phase, the environment and human societies were made more susceptible to microbial and chemical hazards, as well as natural disasters. Hence, the management of the environment with a holistic view is needed for sustainable urban development. The objective of this two-week GFE is to let the participants learn about i) various environmental risks associated with urbanization and ii) environmental management in Bangkok through lectures and field visits.

Since we, the participants, were from different academic backgrounds, the lectures served as effective introduction to the whole field exercise since it ensured that we all had the same basic knowledge on the effects of urban environment to human health. The lectures also served as avenues for the student participants to ask pressing questions to government officials.

The field visits exposed us to different facilities involved in minimizing different forms of pollution. One was in an air emissions testing center where the laboratory rooms and a demonstration of how the testing is done on vehicles were shown. Another was in Dindaeng’s Wastewater Treatment Plant where the different stages of transforming water into a potable one were thoroughly explained to us. Last was in Nonthaburi’s Landfill Site where we got to see the vast area of land dumped openly with unsegregated trash in what was supposed to be a sanitary landfill.

After being equipped with theoretical and hands-on knowledge, we were given three days to conduct a small-scale research related to urban health. We were divided into four groups, which tackled various issues. This year, the final researches done were 1) Knowledge, Perception on Air Pollution and the Preventive Behaviors among Mobile Vehicles Drivers  in Bangkok, Thailand, 2) Assessing Knowledge on Urban Heat Island Phenomenon in Human Health in Bangkok, 3) Integrated Solid Waste Management of Nonthaburi Province, Thailand, 4) Assessment of Air pollution Caused by Boats in Saen Saep Canal. All of the groups performed questionnaire surveys as part of the methodology. This gave us the opportunity to interact with the locals and understand their plight better. We were then asked to present the results of our studies and our corresponding recommendations on the last day of the program.

All in all, the program was well organized. It made us interact and learn from the lecturers, key persons and from our co-participants as well. We also got to see how some environmental issues are being addressed with only band-aid solutions particularly in developing countries due to lack of technical know-how, capability and funding. Comprehensive systemic solutions are what they need so it would be best if more collaborations between different stakeholders and sectors would be promoted further. These countries could learn a lot from developed ones especially Japan since the country was plagued with environmental problems in the late 20th century due to rapid industrialization but has dramatically recovered since then.


In Search for Livelihood in Zhangye, the Silk Road Gatetown to China

Rene Castro Blog, Reports November 11, 2015


GPSS-GLI Oasis Unit seeks to understand how people in Zhangye, in Gansu Province of China, a region facing a severe water scarcity, observe the past five years in order to help the local policymakers evaluate their regulation.

The City of Zhangye, located on the southern edge of Gobi Desert, entirely depends for its water supply on Heihe River that carries snowmelt from Qilian Mountain to the South.

The City of Zhangye, located on the southern edge of Gobi Desert, entirely depends for its water supply on Heihe River that carries snowmelt from Qilian Mountain to the South.

Today, water scarcity attracts utmost attention worldwide. Lake Chad, located at the intersection between Chad, Cameroon, Nigeria and Niger, once posed a threat to the locals’ livelihood when its area shrank almost 95% over the latter half of the 20th century (though the situation has somehow improved to date). A similar threat has confronted people on the other side of the Atlantic Ocean. There had not been a significant amount of rain in the State of California until the recent extreme flooding. Some hard measures, such as use restrictions, were taken to cope with the severe water scarcity. Across the Pacific Ocean, we also find societies in deserts and drylands which have been dealing with difficulties of the like. Zhangye City, Gansu Province in China, is one of them.

Figure 1: “Planetary Boundary” by Kate Raworth

Figure 1: “Planetary Boundary” by Kate Raworth

Efforts are being made to mitigate and adapt to the situation. Chinese authorities, both national and local, have five-year guidelines since 1953 (it was first called plans but recently is called guideline to reflect the country’s shift to a market economy). They describe the development goals to be achieved in the next five years, and 2015 is the last year of the 12th five-year guidelines. Zhangye’s 12th guideline outlines how the city will commit to developing its economy in an environmentally sustainable way. One of their goals is construction of the local ecology supported with monitoring and evaluating systems for various resources including the scarce water.

Coordinated by Heng Yi Teah, a doctoral student, a team of five graduate students from GPSS-GLI, with assistance from Professor Eiji Yamaji, Assistant Professor Tomohiro Akiyama and Academic Staffer Izumi Ikeda, visited Zhangye City seeking to help the local government assess their policy implementation. They tried to do so by informing the government how people in the city observe the local environmental and socio-economic changes in the past five years, and how these observations are related to the evaluation of the villagers’ own livelihoods. The students gained the information by interviewing farmers at more than twenty villages in Zhangye.

For identifying the environmental factors to ask questions about, the conceptual framework of planetary boundary (see Figure 1) was adopted. This famous framework was proposed by Kate Raworth who is known as a doughnut economist; her idea is that there are limits for resource exploitation and pollution (environmental ceiling) within which economic activities can be sustained, while there are minimum requirements for development to fulfill the basic human rights (social foundation).

Figure 2: Interview at Xiejiawan, a village north to Zhangye National Wetland Park

Figure 2: Interview at Xiejiawan, a village north to Zhangye National Wetland Park

Among the factors shown in Figure 1, the students chose the quality and quantity of available water (freshwater use), air quality (atmospheric aerosol loading), the use of pesticide/herbicide (nitrogen and phosphorus cycle & chemical pollution) and the area of wetland reclaimed from farmland (land use change) as the key variables to interview the farmers about.

The team spent five days to conduct interviews around Heihe River, the chief water source of the city. During the interviews, GPSS-GLI students were joined by Shengnan Zhou and Bingyu Wang, two local students at the Cold and Arid Regions Environmental and Engineering Research Institute (CAREERI) of the Chinese Academy of Sciences (CAS), to make the conversations with the farmers smooth. From the upper to lower reaches of the river, the dominant landscape is cornfield. All houses in the farmlands are very similar, and oftentimes their outer walls are connected to one another. Around the entrance of each house are signs with Chinese letters, phrases showing wishes for peace and happiness (see Figure 2). All the houses visited were dwelled by friendly owners.

The results are still being analyzed and will shortly be reported.


In the front (from the left): Ricardo San Carlos, Shengnan Zhou (CAREERI), Sijia Zhao and Heng Yi Teah; In the Back: Norikazu Furukawa, Orlando Vargas Rayo, Tomohiro Akiyama, Izumi Ikeda and Bingyu Wang (CAREERI).

In the front (from the left): Ricardo San Carlos, Shengnan Zhou (CAREERI), Sijia Zhao and Heng Yi Teah;
In the Back: Norikazu Furukawa, Orlando Vargas Rayo, Tomohiro Akiyama, Izumi Ikeda and Bingyu Wang (CAREERI).

SOLAR SHARING IN JAPAN: Opportunities and Experiences

Rene Castro Blog, Reports July 30, 2015

By: Slavka Batorova (GPSS Alumni)

Our most plentiful renewable source of energy is the sun. Technology that harnesses this power – solar photovoltaics (PV) – has experienced a rapid worldwide growth, but this growth also exposed its drawbacks and raised new challenges.

A major drawback of solar PV systems is their significant land use. Large scale PV facilities are installed directly on the ground, including farmland. Unsurprisingly, paving farmland with solar panels has drawn criticism for curtailing food production potential and destroying landscapes and biodiversity. Until recently, the prevalent mindset was that a piece of land can be used either for food or for energy production, but not for both. This mindset was overturned by the Japanese invention of “solar sharing”, which made it possible to produce food and renewable energy on the same land at the same time.

Although invented a decade ago, solar sharing went almost unnoticed until the Fukushima Daiichi nuclear disaster in March 2011. The disaster changed Japan’s energy policy and led to greater focus on renewable energy. Japanese government introduced a renewable energy feed-in tariff (FIT) scheme in July 2012, which made it mandatory for electric power companies to buy electricity from renewable sources at fixed prices for 10-20 years.

Solar sharing is based on the fact that most plants do not need all the sunshine they receive in an open field. Everything beyond the plant’s light saturation point does not increase photosynthesis rate and can even be harmful (e.g. causing lack of moisture). If crops do not need all the sunlight, why not use the excess for power generation?

The first one to combine this fact with solar power generation was Akira Nagashima. He proposed solar sharing in 2004, patented his invention and made the patent free for public use in 2005.

I graduated from Sustainability science master course in 2010, so I do have some academic background in topics like renewable energy. I remember discussing many interesting sustainability related topics in the class, but looking back now, I must admit they were quite abstract terms to me at the time.

Building a solar sharing power plant – which I believe is part of a sustainable solution to some old problems – was an opportunity to experience the practical side of my theoretical background. It was a chance to see the connection between the macro- and the micro-world, between a technology, a national policy and the everyday life.

Our power plant would not exist without Mr. Nagashima’s invention of solar sharing, but just as importantly, it wouldn’t exist without Japan’s feed-in tariff scheme which made solar sharing not just a nice thing to do, but also an attractive investment and source of income. So availability of the right technology and the right policy led to our personal decision to invest our time and money into this and not something else.

People often see national policies as something distant and unrelated to their everyday lives, but every policy is implemented through concrete actions of individuals. Under the big national policy of promoting renewables through feed-in tariff scheme, we took very small, specific steps like dealing with real estate agents when looking for suitable land, submitting and resubmitting application for FIT accreditation, negotiations with solar installation companies for whom solar sharing was as new as it was for me, bringing cold drinks to construction workers to help them survive in the summer heat, waiting for TEPCO to get things done. All these steps were full of compromises when we had to choose from available options rather than from ideal options, but in the end they sum up to a power plant of 40 kilowatts that will once be counted in some ‘abstract’ national statistics on renewable energy. Plus we have a nice place with chickens and sometimes goats where neighbors often stop by for a chat.

Screen Shot 2015-07-30 at 2.23.11 PMToday there are tens of solar sharing power plants in Japan. One of them is our power plant Oo in Tsukuba, Ibaraki prefecture. We (my husband Nobuo and I) built it last year and started raising free-range chickens under the panels this year. To the left is a photo of our chickens.



Why did we build a power plant?

I first learned about the concept of solar sharing in June 2013, when I visited a solar sharing project of Ken Matsuoka (in Tsukuba) who would later become – together with the inventor Mr. Nagashima – one of the pioneers of solar sharing. When I saw his plant, at that time under construction, I instantly became a fan. I realized that I just came across an epochal concept that could once change Japan’s agricultural and energy landscape.

I then visited the inventor Akira Nagashima at his trial site in Chiba prefecture and started English blog because there was no information on solar sharing in English at the time (today there are plenty of English articles). I gradually realized that rather than writing about others, I could build something myself. Nobuo, my husband, liked the idea as well, so we started together – the first step was finding suitable place – and our power plant Oo started producing electricity in November 2014. It will continue to sell electricity to TEPCO for the next 20 years. At an installed capacity of 40 kilowatts, it generates about 4500 – 5000 kilowatt hours of electricity per month, which is enough to cover demand of about 15-20 Japanese families.

In most solar sharing projects, the land under the panels is used to cultivate crops, but in our power plant we decided to raise free range chickens and sell eggs. Neither of us is a professional farmer so chickens are half for fun, half for business.

For more information check my blog:


So for me the lesson was that;

1) It is wise to be interested in government policies because they do have impact on our lives,

2) good policy makers make sure to go to the field and see how their policies are working with the “end-users”, because there are always things to improve.

Solar sharing power plant at Oo, Tsukuba, Japan. July 2015

Solar sharing power plant at Oo, Tsukuba, Japan. July 2015

How does it work?

Solar panels are installed on a frame about 3 meters above the ground. About two thirds of sunlight reaches the ground and the remaining one third hits the panels. Under the panels, crops can be cultivated or animals be raised. In this way, the same area is used simultaneously for both agriculture and electricity generation. Although the amount of electricity produced per square meter is lower in solar sharing than in ground-mounted installations, the fact that solar sharing unlocks vast areas of farmland for energy generation as a by-product of food production means a breakthrough increase in solar power potential.

Graph below shows that if solar sharing was installed on 20% of Japan’s farmland (with a shading rate of 25%), it could produce as much as 474.9 million megawatt hours of electricity annually. This is about 57 % of Japan’s total electricity demand in 2014.


Graph data sources: 

  1. 2014 Electricity Demand – The Federation of Electric Power Companies of Japan(FEPC)
  2. Cultivated acreage (data used to calculate solar sharing output): Ministry of Agriculture, Forestry and Fisheries (MAFF), Japan
  3. Solar power output and wind power output under feed-in tariff (FIT) scheme
  4.  Nuclear power – capacity and utilization rate (used to calculate hypothetical output) (All Japan’s nuclear reactors were shutdown at the time of writing this article). Japan Atomic Industrial Forum

※Calculation of hypothetical output is based on the capacity of 43 reactors classified “in operation” [operation suspended] as of July 15, 2015. Calculation takes into account a pre-Fukushima utilization rate of 70 % (February 2011). Current (July 2015) utilization rate of Japan’s nuclear power is 0 %.

Game development summary: “Let’s find a solution for compensation issue of Minamata disease”

Minamata Team 015 4- Others, Blog, Minamata Unit 2015, Reports May 1, 2015

Game can be an important component for learning in both informal and formal education. It provides an excellent environment for sharing of ideas and discussion even societal issues. The game development group of Minamata Resilience Exercise 2014 aimed to create an interactive game targeting graduate students in a classroom setting, which of its theme focused on the ongoing compensation issues of Minamata Disease.

Our game, “Let’s find a solution for compensation issue of Minamata disease” requires basic understanding in the historical background and socio-cultural issues of Minamata Disease. We recommend you to watch the video produced by our peer prior to playing our game.

Resources for playing our game are shown below for educational use. We hope you will be able to gain further understanding in the complexity of Minamata Disease, and the issues that remain today.

Game development team, Minamata RE 2015

Introduction to Minamata Unit 2015

Minamata Team 015 Blog, Minamata Unit 2015, Reports April 29, 2015

February 27 to March 4, 2015, the University of Tokyo sent ten students from its Graduate Program on Sustainability Science- Global Leadership Initiative and two students from its Department of Urban Engineering to Minamata City to study the issues behind the Minamata Disease via stakeholder interviews and site visits. This resilience exercise is conducted once in two years. Traditionally, group’s outputs are written review reports. This time, the group aims to produce laypeople-friendly knowledge on the disaster via a blog, a video and a game in order to increase general awareness on the disaster.

The blog consists of three parts-1. Daily Blog Post (Archiving the activities during the trip), 2. The Story in 8 Posts (The concise knowledge to understand Minamata), 3. 八则水俣病的通识课 (The Chinese version for part 2.).

Author: Minamata Unit 2015; This website is created by Mahdi Ikhlayel.

An Introduction to the Minamata Disease (1)|What is the Minamata Disease?

Minamata Team 015 2-The Story in 8 Posts, Blog, Minamata Unit 2015, Reports April 28, 2015

The Minamata Disease refers to the symptoms exhibited as a result of Mercury toxicity which was caused in this case, by water-borne Methyl Mercury pollution. As the disease largely affected residents in the vicinity of Minamata Cityw within Kumamoto Prefecture (Figure 1), it was termed as the “Minamata Disease”. Sufferers of the Minamata Disease exhibit symptoms synonymous with the Hunter-Russel syndrome, which was in turn, founded on research on Mercury poisoning resulting in consumption of seed preservatives in England during the 1930s. Hunter-Russel symptoms include: sensory disorder, ataxia, visual field constriction, impaired hearing and speech impairment. Among the victims of the Minamata Disease, initial symptoms exhibited by acute-sufferers include disorientation, which may result in death in a few months; however, thousands of sufferers who have a range of milder symptoms still exist today. Accurate diagnosis of sufferers, regardless of the severity of their symptoms, has proven difficult, resulting in a multitude of legal, social, political and medical disputes over a span of 60 years (and counting).


Figure 1: Map showing location of Minamata city, Kumamoto Prefecture; (inset) map showing the location of Chisso Cooperation’s factory, and its wastewater discharge point, Hyakken Harbour .Inset image credits: Modified from “Map of Minamata Bay and the Chisso Factory”, Wikipedia, CC BY-SA 3.0.

Author: Joanne Khew; Figure by Joanne Khew; Contributors: Mahdi Ikhlayel, Heng Yi Teah, Angeli Guadalupe

An Introduction to the Minamata Disease (2) |Chisso Factory and Mercury Pollution

Minamata Team 015 2-The Story in 8 Posts, Blog, Minamata Unit 2015, Reports April 27, 2015

Chisso Cooperation is a major Japanese company. In its early years (1908), Chisso was inaugurated at Minamata city where it utilized the neighbouring high mountains with its natural streams as a resource for hydroelectricity generation for the production of fertilizers. Mercury was only used in Chisso’s industrial processes in 1932 when Mercury Oxide was utilized as a catalyst in the synthesis of acetaldehyde. However, the Mercury Oxide catalyst is reduced in the process of acetaldehyde production. For continued acetaldehyde production, oxidation of the reduced catalyst was carried out using Permanganate (MnO4) in a method specially devised by Chisso. This method was later changed in 1951 to the prevailing, commercial method of using Ferric Iron (Fe3+) and nitric acid as replacements for Permanganate. Although this change was suspected to be the cause of the onset of the Minamata Disease in 1952 and 1953, scholars were unable to pinpoint with certainty that the source of mercury pollution originated from the wastewater released into the Minamata Bay from Chisso’s acetaldehyde production process. Chisso also did not help investigations and attempted to deflect responsibility up till 1966 where they were forced by legal decree to stop acetaldehyde production (Figure 2: Timeline of important events). Furthermore, Chisso raised two main objections in the process of their trail: If they were truly the culprits, 1) why did victims of the Minamata disease only appear in the 1950s, although they started the acetaldehyde synthesis process in the 1930s; and 2) why were victims only found in the vicinity of Minamata city, although acetaldehyde synthesis was carried out in factories around the world?


Figure 2: Timeline of important events concerning Chisso factory and Mercury pollution.

Author: Joanne Khew; Figure by Joanne Khew; Contributors: Mahdi Ikhlayel, Heng Yi Teah, Angeli Guadalupe

An Introduction to the Minamata Disease (3) |Examining the cause of the Minamata Disease (1)

Minamata Team 015 2-The Story in 8 Posts, Blog, Minamata Unit 2015, Reports April 26, 2015

Around the 1950s/1960s, even when it was scientifically proven that the Minamata Disease (previously termed by laymen as the strange disease) was caused by water-borne mercury, Chisso was aware that their wastewater contained traces of mercury. This was due in part to an experiment whereby Chisso authorized local researchers to feed cats wastewater contaminated food, resulting in cat #400 developing symptoms typical of the Minamata Disease (movement dis-coordination). Despite this, Chisso refused to acknowledge and amend their faults. Unknowing to them, the buried truth of the experiment would eventually come back to affront them in the future. Today, a tombstone commemorating the death of the cats used in Chisso’s wastewater toxicity experiment stands outside Soushisha’s Minamata Disease Museum as a permanent reminder of Chisso’s fault as perpetrator in the Minamata Disease Incident.

Besides the aforementioned experiment, other evidence exist to trace Chisso’s responsibility in causing the Minamata Disease outbreak in 1953. According to research by Professor Nishimura (The University of Tokyo), Chisso initially (1931) utilized their own process for oxidizing the Mercury Oxide catalyst reduced during the process of acetaldehyde synthesis in order to avoid paying the high patent cost attached with the prevalent commercial method. Chisso’s process involved using Permanganate (MnO4) as an oxidizing agent while the prevalent commercial method has Ferric iron (Fe3+) . However, the reason behind the effectiveness of Chisso’s method was ironically due to the presence of Ferric iron impurities in the Permaganate oxidizing agent. Chisso’s method also coincidentally lowered the production of Methyl Mercury to about a tenth of what would have been produced if the commercial method had been used. During the post-war years, when rebuilding and hence, material production (e.g. PVC) was important, Chisso switched their method of acetaldehyde synthesis to the commercial method, which utilized Ferric iron, in order to increase their production output. This method required the use of another oxidizing agent (Nitric Acid), to oxidixe the reduced Ferric Iron (Fe2+) back to Fe3+ (Figure 3), producing even more Methyl Mercury in the process. However, why did this commercial and widely used method result in a serious case of mercury poisoning only in the vicinity of Minamata city?

Screen Shot 2015-04-29 at 7.19.45 PM

Figure 3: Chisso’s acetaldehyde synthesis process and two alternate routes to oxidize Mercury Oxide catalyst, and the corresponding amounts of Methyl Mercury (the organic compound which causes Mercury toxicity in the Minamata Disease).

Source: Adapted from the Science of Minamata (水俣病の科学)

Author: Joanne Khew; Figure by Heng Yi Teah; Contributors: Mahdi Ikhlayel, Heng Yi Teah, Angeli Guadalupe

An Introduction to the Minamata Disease (4) |Examining the cause of the Minamata Disease (2)

Minamata Team 015 2-The Story in 8 Posts, Blog, Minamata Unit 2015, Reports April 25, 2015

In reality, the Minamata Disease did not just occur in Minamata City (and its vicinity). In 1965, Methyl Mercury was also released by a factory into a river in Niigata, resulting in people around the vicinity exhibiting a range of Mercury toxicity symptoms. However, what was different in the case of Methyl Mercury discharge in the case of Showa Denko (Niigata) and Chisso (Minamata City) was that the latter was situated nearer to the sea and hence wastewater was discharged directly into the ocean waters. According to Professor Nishimura’s research (The Science of the Minamata Disease -水俣病の科学), the concentration of Chlorine ion present in solution would affect the solubility of the Methyl Mercury compound. When wastewater containing Methyl Mercury is discharged directly into seawater (as in Chisso’s case), the high concentration of chlorine ions present readily combine with it to form the soluble Methyl Mercury Chloride compound. This compound is highly mobile in water and can be easily taken into body tissue of sea-creatures and humans that directly or indirectly ingest the polluted water.

In the case of mercury pollution in Niigata, mercury-containing wastewater was discharged into a river where concentration of chlorine ion is comparatively lower than seawater. The Methyl Mercury ion then conjugates with abundant organic debris present in the river water (e.g. protein colloids, algae) and sinks into the riverbed. As Methyl Mercury in this form is insoluble and therefore, not mobile, it is not as readily transferred to the human body. However, mobility of this form of Methyl Mercury can occur when it is consumed by benthic organisms as sediment; and biologically magnified up the food chain; or when it is transported to the sea along with riverbed sediment through erosion (Figure 4). Once at the sea, the Methyl Mercury ion trapped in the insoluble compound can recombined with the abundant supply of chlorine ions in the seawater, forming soluble Methyl Mercury Chloride. In Chisso’s case, seawater was also used for the cooling of factory reactors, resulting in the formation of more Methyl Mercury Chloride when seepage occurred. As such, this post, combined with the previous one [Examining the cause of the Minamata disease (1)], thus answers the two questions posed by Chisso on the post: An Introduction to the Minamata Disease (2) |Chisso Factory and Mercury Pollution.


Figure 4: The different forms of Methyl Mercury: i. The case of Minamata City where Methyl mercury is released directly into the sea; ii. The case of Niigata where Methyl Mercury is released into the river and conjugated with sediment

Source: Adapted from the Science of Minamata (水俣病の科学)

Author: Joanne Khew; Figure by Heng Yi Teah; Contributors: Mahdi Ikhlayel, Heng Yi Teah, Angeli Guadalupe

An Introduction to the Minamata Disease (5) |The Spread of Wastewater, Biomagnification and the Fishermen’s catch

Minamata Team 015 2-The Story in 8 Posts, Blog, Minamata Unit 2015, Reports April 24, 2015

Once Methyl Mercury from Chisso’s wastewater enters the Minamata bay in soluble form, pollution would continue to spread throughout the whole bay. Because industrial waste is comprised mainly of freshwater, its spread (direction and extent) is determined by the salinity of the seawater that it is discharged into. In addition, the Methyl Mercury is taken up through the gills of oceanic organisms or through ingestion of contaminated prey. Methyl Mercury persists in the tissue of marine organisms for about 72 days and is biologically magnified up the food-chain. As such, the movement of fish within the Minamata bay further serves to widen the range of Mercury pollution. Minamata bay is situated within the Shiranui Sea, which is bordered by many islands and landforms, making it a considerably closed system with a prominent north to south current. Fish tend to gather and traverse within the Shiranui sea along the main current and thus form the bulk of the fishery catch from fishermen residing in the surrounding islands and lands. Consumption of mercury-contaminated fish was then a major factor that resulted in the spread of pollution to areas bordering the Shiranui sea. Furthermore, the spread of the Minamata Disease could also be attributed to the population’s lack of knowledge of seeking the proper medical treatment. The fishermen who were affected by the Minamata Disease in the islands around the Shiranui sea were also not volunteering themselves for relevant physical examinations in fear that their catch would be banned from the markets due to discrimination against their physical condition. These fishermen usually exhibited non-acute symptoms of mercury poisoning but also had difficulty applying for medical aid due to complications in the certification system. Even up to today, only a fraction of the victims in the islands bordering the Shiranui sea are officially certified as Minamata Disease Patients (Figure 5), leaving the support of “forgotten victims” to several non-governmental organizations.


Figure 5: Fishermen’s catch location in the Shiranui sea, where Minamata bay is situated; and the geographical status of official Minamata Disease patient certification.

Author: Joanne Khew; Figure by Joanne Khew; Contributors: Mahdi Ikhlayel, Heng Yi Teah, Angeli Guadalupe