The old church of Geamana village is seen partially submerged by polluted water tainted with cyanide and other chemicals near Rosia Montana, central Romania, March 24, 2014. (Photo by Bogdan Cristel/Reuters)

A South Korean soldier wear North Korea's military uniform, acting as North Korean soldier during an anti-terror and anti-chemical drill session held as part of the 2011 Ulchi Freedom Guardian (UFG) event on August 17, 2011 in Seoul, South Korea. The 11-day UGC, which features drills including the handling of chemical and biological attacks, is a regular joint exercise between US and South Korean troops to prepare for potential emergencies on the Korean Peninsula. (Photo by Chung Sung-Jun/Getty Images)

A woman walks past as South Korean soldiers participate in an anti-chemical and anti-terror exercise as part of the 2023 Ulchi Freedom Shield (UFS) at subway station on August 22, 2023 in Seoul, South Korea. The 11-day exercise, which features drills including the handling of chemical and biological attacks, is a regular joint exercise between U.S. and South Korean troops. (Photo by Chung Sung-Jun/Getty Images)

Only after World War II did the secret spill: Ōkunoshima, located in the Inland Sea of Japan between Hiroshima and Shikoku, was the top-secret site for manufacturing chemical warfare. When the factories were closed down, a number of exotic wild rabbits were seen freely roaming the island. They were assumed to have been the test subjects for the chemical weapons, which the military failed to eradicate when the factory was demolished.

A labourer pulls a cart loaded with sacks of spices at a wholesale spice and chemical market in the old quarters of Delhi, India, December 19, 2016. Picture taken December 19, 2016. (Photo by Adnan Abidi/Reuters)

South Korean emergency services personnel wearing protective clothing participate in an anti-terror and anti-chemical terror drill on the sidelines of the joint South Korea-US Ulchi Freedom Shield (UFS) military exercise, at a shopping mall in Seoul on August 23, 2022. (Photo by Anthony Wallace/AFP Photo)

South Korean rescue members wearing chemical protective suits walk past a monster character (R) during an anti-terror drill as part of a disaster management exercise at the COEX shopping and exhibition center in Seoul on May 20, 2016. South Korea is holding its 2016 Safe Korea anti-disaster exercise this week against terrorist threats and natural disasters. (Photo by Jung Yeon-Je/AFP Photo)