History of the Use and Epidemiology of Organophosphorus Poisoning

Organophosphorus (OP) compounds are organic derivatives of phosphorus that have largely been used as pesticides and nerve agents. Tetraethylpyrophosphate was synthesized in 1854 as the first OP cholinesterase inhibitor. During 1934–1944, Gerhard Schrader, a German chemist at I. G. Farben industries and his coworkers synthesized about 2,000 OP compounds, including parathion as a pesticide and tabun, sarin, and soman as chemical warfare nerve agents. Although the nerve agents had been produced in Germany, they were not applied during World War II (WWII). At the end of WWII, the chemistry of OP compounds developed rapidly. The main use of nerve agents has been reported during the Iran–Iraq war (1980–1988). The Iraqi army used tabun and sarin against the Iranian troops (Majnoon Island) and civilians in Halabjah. In the 1990s, OP nerve agents have gained prominence as weapons of mass destruction and chemical terrorism. The use of sarin in chemical terroristic attacks has been reported during 1994–1995 in Matsumoto and Tokyo subway lines, Japan. Today, a wide range of OPs with a variety of biological properties are available for agricultural and public health usages including insecticides, nematocides, acaricides, and fungicides. As a result of the widespread use of OPs, OP poisoning is a major cause of morbidity and mortality worldwide, especially in developing countries. OP poisoning shows demographic, seasonal, and regional variations. However, the pattern of OP poisoning is different in developed and developing countries. In this chapter, we reviewed the history of the use and epidemiology of OP poisonings.