The occurance of chemical contamination in Japan

For example, the "Ashio copper mine poisoning incident," which came to light in the late 1800s, is famous as the first case in which pollution became a social problem in Japan.
In addition, during the period of rapid economic growth, the so-called "four major pollution diseases" such as Minamata disease, Niigata Minamata disease, Yokkaichi asthma, and Itai-itai disease occurred. These diseases have caused serious damage. After the "Four Major Pollution Diseases" became a problem, efforts to eliminate pollution began to be made throughout the country. As a result, the Basic Law on Pollution Control was enacted in 1967, the Headquarters for Pollution Control was established in the Cabinet in 1970, and the Environment Agency was newly established in 1971.

Minamata disease occurred around 1956 in the coastal area of Minamata Bay in Kumamoto Prefecture. Methylmercury produced in the manufacturing process of a certain factory was washed from the river to the sea and accumulated in high concentrations in the fish and shellfish of Minamata Bay. People who ate the fish and shellfish suffered from symptoms of poisoning such as narrowing of vision, paralysis of limbs, and even death. Later, around 1964, an outbreak occurred in the Agano River basin in Niigata Prefecture. Itai-tai disease, which became a major social problem in the 1950s, occurred in the Jinzu River basin of Mt. Fuji. Cadmium flushed from the mines entered the Jinzu River, accumulated in the soil of rice paddies drained by the river, and entered the bodies of the residents through rice and domestic water. As a result, their bones became fragile and sometimes resulting in death due to the effect of the chemicals making the body frail.