Tabun (nerve Agent) - Effects of Overexposure

Effects of Overexposure

The symptoms of exposure include: nervousness/restlessness, miosis (contraction of the pupil), rhinorrhea (runny nose), excessive salivation, dyspnea (difficulty in breathing due to bronchoconstriction/secretions), sweating, bradycardia (slow heartbeat), loss of consciousness, convulsions, flaccid paralysis, loss of bladder and bowel control, apnea (breathing stopped) and lung blisters. The exact symptoms of overexposure are similar to those created by all nerve agents. Tabun is toxic even in minute doses. The number and severity of symptoms which appear vary according to the amount of the agent absorbed and rate of entry of it into the body. Very small skin dosages sometimes cause local sweating and tremors accompanied with characteristically constricted pupils with few other effects. Tabun is about half as toxic as sarin by inhalation, but in very low concentrations it is more irritating to the eyes than sarin. Also, tabun breaks down slowly, which after repeated exposure can lead to build up in the body.

The effects of tabun appear slowly when tabun is absorbed through the skin rather than inhaled. A victim may absorb a lethal dose quickly, although death may be delayed for one to two hours. A person's clothing can release the toxic chemical for up to 30 minutes after exposure. Inhaled lethal dosages kill in one to ten minutes, and liquid absorbed through the eyes kills almost as fast. However, people who experience mild to moderate exposure to tabun can recover completely, if treated almost as soon as exposure occurred. The LCt50 for tabun is about 400 mg-min/m3

Treatment for suspected tabun poisoning is often three injections of a nerve agent antidote, such as atropine. Pralidoxime chloride (2-PAM Cl) also works as an antidote; however, it must be administered within minutes to a few hours following exposure to be effective.