Organophosphates are a group of chemicals that have many domestic and industrial uses, though they are most commonly used as Insecticides and are responsible for a number of poisonings. The main mechanism is blocking the enzyme acetylcholinesterase causing nervous and respiratory damages that result in the insects death, but they are also hazardous to humans. After the cessation of use of organochloride insecticides, they became the most commonly used Pesticides and are responsible for 70% of pesticidal use in the United States (#PANNA).
Main article: Chemical Weapons
Organophosphates were originally developed in the 1940s as highly toxic biological warfare agents. This group of compounds are referred to as Nerve Agents and their modern derivatives are Sarin, soman, and VX.
Researchers created many compounds hoping to be able to find ones that would target characteristics of certain species, thus limiting their unwanted effects. When the organophosphate Parathion was first employed as a replacement for DDT a number of workers accustomed to handling the less toxic DDT were killed.
Though the chemical structures of organophosphates and Carbamates are very different, the mechanisms are the same. They block the aceytlcholinesterase enzyme needed remove the acetylcholine from the reaction.
Organophosphates are used in a variety of settings, though they are mostly associated with Nerve Agents or Chemical Weapons and Pesticides, though they are also used in industrial settings occasionally (#Katz, 2006).
Nerve agent or organophosphate poisoning results in a wide range of exposure because it affects a large number of organs and physical processes. Below is a list retrieved from the CDC site on nerve agent exposure.
There are a number of alternatives to organphosphates:
Pesticides are responsible for a huge number of poisonings throughout the world. Organophosphates are readily available throughout the world. The American Association of Poison Control Centers estimate that 4.2%, or over 102,000, of all poisonings in America are due to Pesticides (#eMedicine). The compounds most frequently involved with the most serious poisonings are Malathion, dichlorvos, and Trichlorfon.
Kamel F and Hoppin JA. Association of pesticide exposure with neurologic dysfunction and disease. Environ Health Perspect. 2004 Jun;112(9):950-8. Available online at EHPonline.
MMWR (1999). Farm worker illness following exposure to carbofuran and other pesticides - Fresno County, California, 1998. February 19, 1999, 48(6), 113-116.
Dean, S. R., & Meola, R. W. (2002). Effect of diet composition on weight gain, sperm transfer, and insemination in the cat flea (Siphonaptera: Pulicidae). J Med Entomol, 39(2), 370-375.
Dryden, M. W., & Gaafar, S. M. (1991). Blood consumption by the cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae)
Dr. Kenneth Katz and Daniel Brooks. "Toxicity, Organophosphates". Aug 31, 2006. Retrieved May 24, 2007 from eMedicine.
Pesticide Action Network North America. "Phase-Out Organophosphate Pesticides: Children & Workers Matter". Retrieved on 5-24-07.
J. Routt Reigart, M.D. and James R. Roberts, M.D., MPH. Recognition and Management of Pesticide Poisonings, 5th ed.. Washington, D.C. (Environmental Protection Agency, 1999). Accessed 5-24-07.