Four Big Pollution Diseases of Japan
Industrial pollution caused four major disease outbreaks in 20th-century Japan.
Japan’s four big pollution diseases were twentieth-century toxicological disasters caused by corporations that mishandled industrial waste. The first outbreak began in 1912; the other three occurred during the 1950s and 1960s. These cases established legal precedents in private tort and civil law for compensating technology-related mass harm, and they continue to influence Japanese court rulings today.
Quick Facts
- First outbreak
- 1912
- Location of first outbreak
- Toyama Prefecture
- Other outbreaks occurred
- 1950s and 1960s
- Environmental agency created
- 1971
Facts from the source article.
Itai-itai disease
Itai-itai disease first occurred in 1912 within Toyama Prefecture. The name translates to "it-hurts it-hurts disease," the phrase affected people would frequently cry out. Cadmium poisoning in drinking water from the Jinzū River basin was determined as the cause, with the source traced to Mitsui Mining and Smelting Company, which began discharging cadmium into the river in 1910. People who drank the water or ate food grown with it, such as rice, were likely to show signs. Initial symptoms included spine and leg pain; later symptoms encompassed debilitating pain, bone fractures from mild traumas, skeletal deformities, anemia, and kidney disorders. Most patients were confined to bed because walking caused severe pain. Residents filed a lawsuit in 1968 and won, leading to negotiations. Mitsui Mining formally admitted responsibility and was obliged to pay recovery costs for the land, ensuring it was returned to a safe and cultivable state.
Minamata disease
Minamata disease was first reported in 1956 in Minamata, a town in Kumamoto Prefecture. Many of the earliest victims went insane from their symptoms, and some died within a month. After a thorough investigation, the illness was identified as methylmercury poisoning, caused by eating fish contaminated with the heavy metal from Minamata Bay. The methylmercury attacked the central nervous system, leading to symptoms like numbness in the arms and legs, loss of balance, fatigue, ringing in the ears, tunnel vision, hearing loss, and slurred speech. Most patients had a mix of these symptoms rather than all of them. The source of the contamination was traced to the Chisso Corporation, which dumped methylmercury into the bay. Chisso made acetaldehyde using water, acetylene, mercury(II) sulfate as a catalyst, and either manganese dioxide or, after August 1951, ferric sulfide as a co-catalyst. The use of ferric sulfide created methylmercury as a byproduct, which was then released as waste. Chisso continued using these catalysts and dumping the byproduct until 1966. Today, the company pays compensation to all officially recognized patients. Over 50 hectares of the bay were reclaimed using the contaminated sludge, topped with clean soil. In 1970, Japan passed the Water Pollution Control Act, requiring factories to regulate dangerous chemical disposal. In 1977, the government began cleaning the bay by vacuuming out 1.5 million cubic meters of sludge and using it to reclaim more than 50 hectares. In 1997, after 14 years and $359 million, the governor of Kumamoto Prefecture declared Minamata Bay safe.
Niigata Minamata disease
In 1965, patients in Niigata Prefecture exhibited signs of Minamata disease, caused by methylmercury poisoning in the Agano River basin. This second outbreak was discovered early on, and its degree was minimal compared to the first in Kumamoto Prefecture. Investigation was given to the Niigata University medical department. Possible causes included several plants using mercury in production, agricultural chemicals, and an earthquake that occurred a year before the disease was discovered. Symptoms were similar to Minamata disease: numbness in the arms and legs, impairment of balance, fatigue, ringing in the ears, tunnel vision, loss of hearing, and decrease in communication skills. In spring 1966, the research team determined the most likely cause was dumping of methylmercury from Showa Denko Corporation factory, located upstream on the Agano River. Showa Denko produced methylmercury as a by-product and dumped it into the river, declining all charges of fault. After controversy, Showa Denko was found guilty of negligence and forced to pay compensation to all affected. In the year of discovery, 26 people were designated disease patients, and five died.
Yokkaichi asthma
Yokkaichi, a city in Mie Prefecture known as the "town of petroleum," produces almost a quarter of Japan's petroleum. Construction of the first oil refinery began in 1955, after which many respiratory diseases emerged in the city and neighboring districts. In the city's center was the largest heavy oil-fired power station and refinery in Japan at the time, which lacked equipment to lower sulfur dioxide emissions before release. In the early 1960s, respiratory diseases emerged in the general population and were specified as Yokkaichi asthma. Five to ten percent of inhabitants aged 40 in Yokkaichi were reported to have chronic bronchitis, whereas less than three percent had the same disease in non-polluted areas. A public release system for air pollution was established in 1965, providing payments to people in the Yokkaichi area who met criteria including specific diseases (bronchial asthma, chronic bronchitis, pulmonary emphysema, and their complications), residence in areas where prevalence increased, and three years of residence within the specified area. Today, many laws regulate the amount of sulfur dioxide a factory can release.
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