Minamata is a small factory town dominated by the Chisso Corporation. The town faces the Shiranui Sea, and Minamata Bay is part of this sea. In Japanese, “Chisso” means nitrogen. The Chisso Corporation was once a fertilizer and carbicle company and gradually advanced to a petrochemical and plastic-producing company. From 1932 to 1968, Chisso Corporation, a company located in Kumamoto, Japan, dumped an estimated 27 tonnes of mercury compounds into Minamata Bay. Kumamoto is a small town about 570 miles southwest of Tokyo. The town consists of mostly farmers and fisherman. When Chisso Corporation dumped this massive amount of mercury into the bay, thousands of people whose normal diet included fish from the bay unexpectedly developed symptoms of methylmercury poisoning. The illness became known as the “Minamata disease”. The mercury poisoning resulted from years of environmental destruction and neglect from Chisso Corporation.
In 1907 the villagers of Minamata convinced the founder of Chisso Corporation to build a factory in their town, hoping to benefit from the wealth of industrialization. The owner, Jun Noguchi, agreed to the development but used the people from Minamata as simple factory workers. The more elite positions, such as engineers and managers, were “imported” as he termed it, from the finest universities, like Tokyo University.
By 1925, the Chisso Corporation was dumping waste into Minamata Bay and destroying the fishing areas. The theory behind Noguchi’s industry was to pay off the Minamata fisherman in exchange for damaging their fishing environment. According to Eugene Smith’s interview of the people who lived in Minamata, the company believed that it was much cheaper to pay off the few people who were opposed to the dumping, rather than implement an environmentally safe technique of waste removal. Therefore, since the villagers accepted this practice through compensation of money, and the government was behind the industry, the entire process appeared ethical.
Chisso Corporation started developing plastics, drugs, and perfumes through the use of a chemical called acetaldehyde in 1932. Acetaldehyde is produced using mercury as a compound and was key component in the production of their products. The company was considered an economic success in Japan, particularly because it was one industry that maintained development despite Japan’s suffering throughout and right after World War II. As other companies economically ripened during Japan’s post-war period, so did the Chisso Corporation. Sales augmented with Japan’s economic success.
In addition, Chisso Corporation’s sales increased dramatically, considering Chisso was the only manufacturer of a primary chemical called DOP, a plasticizer (dioctyl phthalate). Having a monopoly on the chemical enabled Chisso to expand rapidly. Since Chisso Corporation was the main industry in the small Minamata town, the town’s growth period from 1952 to 1960 paralleled Chisso’s progress.
Not until the mid-1950s did people begin to notice a “strange disease”. Victims were diagnosed as having a degeneration of their nervous systems. Numbness occurred in their limbs and lips. Their speech became slurred and their vision constricted. Some people had serious brain damage, while others lapsed into unconsciousness or suffered from involuntary movements. Furthermore, some victims were thought to be crazy when they began to uncontrollably shout.
People thought the cats were going insane when they witnessed “suicides” by the cats. Finally, birds were strangely dropping from the sky. Series of these unexplainable occurrences were bringing panic to Minamata.
Dr. Hajime Hosokawa from the Chisso Corporation Hospital, reported on 1 May 1956, that, “an unclarified disease of the central nervous system has broken out”. Dr. Hosokawa linked the fish diets to the disease, and soon investigators were promulgating that the sea was being polluted by poisons from the Chisso Corporation. The Chisso Corporation denied the accusations and maintained their production. However, by 1958, Chisso Corporation transferred their dumping from the Minamata Bay to the Minamata River hoping to diminish accusations towards the company.
The Minamata River flows past the town Hachimon and into the Shiranui Sea. The people of this area also began developing the “strange disease” after a few months. The Kumamoto Prefecture government responded by imposing a ban which allowed fisherman to “catch” fish, but not to “sell” fish from the bay. Since this was their main food source, the people continued to eat fish at home, but the ban released government officials from any responsibility for those who developed the illness.
Finally, in July 1959, researchers from Kumamoto University concluded that organic mercury was the cause of the “Minamata disease”. A number of committees, of which Chisso Corporation employees were members, formed to research the problem. The committees denied this information and refuted the direct link of mercury to the strange disease. Finally, Dr. Hosokawa performed concealed cat experiments in front of the Chisso Corporation management and illustrated the effects of mercury poisoning by feeding the cats acetaldehyde. Dr. Hosokawa was the first person who made a valiant effort in proving to Chisso Corporation that they were the ones accountable for the mercury poisoning. After the meeting with Chisso officials, Dr. Hosokawa was restricted from conducting any further research or experiments, and his findings were concealed by the corporation.
Chisso Corporation began to make deals with the victims of the “Minamata disease”. People who were desperate and legally ignorant signed contracts which stated that Chisso Corporation would pay them for their misfortunes but would accept no responsibility. In fact, there was even a clause which read, “if Chisso Corporation were later proven guilty, the company would not be liable for further compensation”.
The fishermen began protesting in 1959. They demanded compensation but soon became intimidated by the threats of Chisso management. The victims feared that if they did not settle, they would never receive any kind of compensation. Chisso paid off some of the people while continuing to profit from increased sales. Chisso installed a “Cyclator” which was designed to treat wastewater. The management, however, often ignored this crucial step in their production process. Not until 1968, did Chisso Corporation quit poisoning the waters in Minamata. The company was forced into court in 1969, and the only reason why the polluting stopped was simply because the method of mercury production became outdated.
It was later determined in court that Chisso Corporation consistently polluted the water of Minamata Bay from 1932 to 1968.
By 1974 only 798 victims had been officially recognized as having “Minamata disease”. Approximately 3000 more people were waiting verification from the board of physicians in Kumamoto Prefecture. Thousands of people continue to eat fish from the Shiranui Sea, but there is no reporting of significant health hazards or mercury poisoning like those people who suffered in Minamata. In 1993, almost 40 years later, victims were still being compensated for damages.
2A.1.1 Itai–Itai Disease
Itai-itai disease was found in the cadmium (Cd)-polluted Jinzu River basin in Toyama Prefecture and has been generally recognized since the 1950s by the effort of inhabitants and Dr. Hagino who was a general practitioner with a private clinic in the polluted area.
Itai-itai disease was officially recognized in 1968 as the first disease induced by environmental pollution in Japan after legal proceedings. The basis of the court decision is simply but clearly shown in “The view of the Ministry of Health and Welfare” which consisted of 7 articles and was announced on 8 May 1968. Especially, the basis that concluded the cause of the disease to be Cd pollution was epidemiological evidence that only cadmium can explain the limited development of itai-itai disease in a specific area around parts of the Jinzu River.
Itai-itai disease is considered to be a type of acquired Fanconi syndrome characterized by renal tubular dysfunction and osteomalacia and has been found among middle-aged and elderly women with relatively frequent pregnancy, living in the cadmium-polluted area for more than 30 years.
A markedly increased excretion of urinary molecular weight proteins such as β2-microglobulin, glucose, protein and amino acids is found in itai-itai disease patients, and these findings are indices of renal tubular dysfunction. Low level of %TRP and metabolic acidosis with high serum Cl are also found. In severe cases increased serum creatinine that shows impairment of renal glomerular function is recognized.
Pathologically, renal damage of itai-itai disease is characterized by atrophic kidney. The weight of the kidney is usually decreased to around 60 g and to 30 g in cases with non-specific inflammation or atherosclerotic change.
Another specific finding of itai-itai disease is osteomalacia. Looser zone is often found in femur, pelvis and ribs. Osteoporosis is also associated with X-ray findings such as unclear trabecular pattern and cortical bone thinning noted.
2A.1.2 Dermatological Problems Due to Arsenic Pollution
Arsenic toxicity in the groundwater in the lower Gangetic delta region has become a serious issue that is confined to middle Holocene sediments. It appears to occur adsorbed on iron hydroxide-coated sand grains and clay minerals and is transported in soluble form and co-precipitated with, or is scavenged by, Fe (III) and Mn (IV) in the sediments. This may be attributed to entrapping in fine-grained and organic-rich sediments during mid-Holocene sea-level rises in deltaic region and was liberated in course of time under reducing conditions. Use of phosphate-rich fertilizer to boost up crop production has aggravated the issue. Arsenic has severe effect on skin. Drinking or exposure to direct water may increase the chance for developing skin infection or dermatitis. Meanwhile, several theories have been proposed, but it is still believed that exposure of skin by any harmful component may initiate pro-inflammatory cytokines. Once any wound is formed due to destructive stimuli, permanent epidermal keratinocyte invites and activates several mediators like Caspase-8 and RIPK3 and those signal transcription factors like nuclear factor-kB, which further release harmful cytokines like interleukin-1β and interleukin-1α. Arsenic not only produces skin diseases and hair fall but also induces the situations like cell stress which triggers other organ damages.