The four big pollution diseases of Japan (四大公害病, yondai kōgai-byō) were a group of man-made diseases all caused by environmental pollution due to improper handling of industrial wastes by Japanese corporations. The first occurred in 1912, and the other three occurred in the 1950s and 1960s. Despite the moniker of 'four' becoming the prominent way to refer to the events, Minamata disease and Niigata Minamata disease were the same pollution disease spread by the same poison, just in different locations.