Abstract
Nerve gas is a chemical weapon and was previously thought to be used solely on the battlefield. This assumption was shattered when Aum Shinrikyo, a new Buddhist sect, sprayed sarin onto a totally innocent civilian population on the night of June 27, 1994, in the quiet town of Matsumoto City in Japan. The sarin terrorist attack in Matsumoto City was a prelude to another attack on an even larger scale that shocked the entire world: the Tokyo subway terrorism with sarin by the same sect, 8 months after the Matsumoto incident on March 20, 1995. For a few months after the Matsumoto City case, no one knew who sprayed the sarin or for what purpose. Even after the Tokyo subway sarin attack and the arrest of many cult members, the detailed information as to how the sarin was detected and made were unknown to the public for many years. Part of the reason was the secretive nature of the Japanese police authority. However, after the passage of 10 or more years detailed information about Aum Shinrikyo's chemical terrorism has become known. In this review, toxicological and chemical aspects of the sarin terrorism incidents are described. It is useful to learn why and how such terrorist attacks took place for the future prevention of chemical and biological agent terrorism.