The Deepwater Horizon oil spill (also referred to as the BP oil spill, the Gulf of Mexico oil spill, the BP oil disaster, or the Macondo blowout) is an oil spill in the Gulf of Mexico which flowed for three months in 2010.
The 2000 Baia Mare cyanide spill was a leak of cyanide near Baia Mare, Romania, into the Someş River by the gold mining company Aurul, a joint-venture of the Australian company Esmeralda Exploration and the Romanian government.
The polluted waters eventually reached the Tisza and then the Danube, killing large numbers of fish in Hungary and Yugoslavia. (Wikipedia)
The Chernobyl Disaster was a nuclear accident that occurred on April 26th, 1986, at the Chernobyl Nuclear Power Plant in the Ukraine.
In December, 1984, a poisonous gas cloud escaped from the Union Carbide India Limited (UCIL) pesticide factory in the city of Bhopal in Madya Pradesh county, India.