A thousand delegates from about 140 nations adopted a treaty Thursday in Kumamoto regulating the use and trade of mercury at an international conference organized by the U.N. Environment Program.

The landmark Minamata Convention on Mercury is named after the Japanese city where industrial emissions of the toxic substance caused a poisoning disease affecting thousands of people.

The pact, which will take effect 90 days after ratification by 50 nations, maps out measures to curb health and environmental damage caused by mercury, "recognizing the substantial lessons of Minamata disease," according to a text of the treaty.