Looks like it started with city cats. In the mid-1950s, residents of Minamata in Japan began noticing that their cats were behaving strangely and falling into the sea on their own. Soon, a mysterious illness appeared in the city.
Minamata residents began to report strange symptoms en masse: numbness of the face, extremities, and difficulty hearing or seeing clearly. Others had physical tremors, difficulty walking, and progressive disturbances suggestive of mental disability. Some screamed uncontrollably and moved strangely. Everything indicates damage to the nervous system.
The first cases appeared in April 1956. Soon a whole “epidemic” of previously unknown disease of the nervous system was discovered. Finally, in July 1959, scientists at Kumamoto University discovered the source of the disease – it was a high level of mercury poisoning. They called it Minamata disease. But how were the villagers poisoned with mercury?
Environmental disaster in Minamata
Minamata is a small fishing town on the coast of the Shiranui Sea. Because of its location, the diet of the inhabitants there is based on the consumption of fish. More importantly, the cats ate the same thing, too. It was the diet that seemed to link those who had symptoms of the disease and the strange behavior of the cats. It then led scientists to suspect that the fish in Minamata Bay had been poisoned.
What could poison the fish in the river and contaminate the main components of the population’s diet? The first suspicions fell on a large petrochemical plant in Minamata. He found that production likely poisoned the water supply. The plant operated by Chisso Corporation denied the allegations and continued production without changing the production method. However, Minamata disease continued to spread. In many people, apart from a number of symptoms of poisoning, a group of concomitant symptoms appeared. Chisso has continued to deny its involvement in the environmental disaster.
High concentration of mercury
A special research team was formed to determine what the disease was and where it came from. Mercury was found to be the causative agent due to the high concentrations found in dead fish and in the organs of the deceased. In February 1959, the distribution of mercury in Minamata Bay was investigated. The results shocked the researchers, as the highest concentrations were concentrated around the sewers of the Chisso plant. It was later discovered that Chisso had dumped approximately 27 tons of mercury compounds into Minamata Bay.
Township fishermen began protesting the Chisso Corporation in 1959. They demanded that the company stop disposing of toxic waste and compensate for the health damage they suffered. Representatives of the company, in turn, tried to deal with the victims in the most beneficial way – so that as few people as possible received compensation. The legal documents they proposed suggested that it would amount to compensation for losses without incurring current or future liability due to the effects of the disease. Many people considered this was their only chance to get compensation and signed the documents. Chisso only stopped poisoning Minimata’s water in 1968.
The catastrophic consequences of the company’s activities
According to the Japanese government, 2,955 people have contracted the disease from Minamata and 1,784 people have been killed. So far, Chisso has paid more than 10,000 people and is still embroiled in lawsuits. In October 1982, 40 plaintiffs sued the Japanese government, claiming that it had failed to prevent the plant from polluting the environment. In April 2001, the Osaka Supreme Court ruled that government regulatory actions should begin by the end of 1959. This was the time when scientists concluded that Minamata disease was caused by mercury poisoning. The court also ordered the Chisso factory to pay $2.18 million in damages.
On October 16, 2004, Japan’s Supreme Court ordered the government to pay $703,000 in compensation to victims of Minamata disease. The environment minister has issued an official apology, and those responsible for Japan’s worst industrial pollution incident have paid the price for their negligence. In 2010, Chisso received an additional order to pay 2.1 million yen and a monthly medical allowance to people whose infection officials had not originally determined. In 1965, a second case of mass mercury poisoning was detected in Japan in Niigata Prefecture, named after Niigata Minamata disease.
Minamata disease. health effects
Minamat’s disease is caused by methylmercury, a byproduct of acetaldehyde production. The central nervous system is the target organ exposed to methylmercury. Affected patients present neurological symptoms including paresthesia, ataxia, dysarthria, narrowing of the visual field, and/or hearing problems. Affected individuals also display psychiatric symptoms (eg mental retardation, mood and behavior disorders). High blood pressure has also been reported to be more common in affected areas.
One particularly troubling aspect of this disease is that methylmercury can be passed on to fetuses. Babies with Minamata disease are born in utero with mental retardation, coordination disorders, limb abnormalities, and many other complications. It is estimated that the number of patients in affected areas who show neurological symptoms of methylmercury poisoning is in the tens of thousands.
Symptoms of methylmercury poisoning
Methylmercury can be absorbed by the body through inhalation, food, and the skin. It binds to proteins and is transported in the blood to tissues and systems, primarily the brain, kidneys and liver. Its toxicity is mainly reflected in the nervous system. The most common symptoms of poisoning include:
- General muscle weakness
- Numbness in the hands and feet
- abnormal vision
- Hearing and speech impairment
- Paralysis and coma
- the death
Mercury in the Oder is not only a threat to animals. The effects can be dramatic
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