Concerning the technological disasters in Japan, we had a lot of pollution issues after the Second World War. We had been seeking economic development first and tended to neglect the side effects. There are four major issues, Minamata disease, Niigata Minamata disease, Yokkaichi asthma, and Itai-itai disease. The issues had been uncovered, especially from the late 1950s to 1960s.
The followings are the youtube videos from TVE we can see the situations.