What is it

VX is a nerve agent that disrupts the transmission of nerve impulses in the body. It is an amber-colored, oily liquid that will remain in the environment until it has been properly cleaned through decontamination methods. It can be similar in appearance to motor oil. VX can enter the body through ingestion, inhalation or through the eyes or skin. VX is the most potent of all nerve agents and the least volatile, meaning it is slower to evaporate. It's approximately 50 times more toxic than cyanide gas.

It was developed by the United States and Britain in the 1950s.

Syntoms

Symptoms of overexposure may occur within minutes or hours, depending on the dose. The symptoms of VX exposure take longer to show up than with other nerve gases, but are similar. They include nausea, vomiting, diarrhea, constriction of the pupils or blurred vision, runny nose, chest tightness, difficulty breathing, disorientation, loss of muscle control, loss of consciousness, convulsions and eventually respiratory failure and death.

Testing

VX exposure is often indicated by several patients presenting with the same symptoms. Testing levels of the enzyme acetylcholinesterase, AchE, in the blood is the best indicator of VX exposure, and droplets often can be seen on the skin. Doctors can also test for arterial blood gases and electrolytes or perform a chest X-ray or EEG to find abnormal breathing activity or irregular heart rhythms.

Recovery Potential

The dose that would be lethal to 50 percent of the people exposed is about 10 milligrams, a tiny amount that could be held on the end of a straight pin. Because the agents act slower than other nerve agents, successful treatment is possible. Once a person recovers, the symptoms are not likely to return, but the patient may suffer from the effects of oxygen deprivation for days or weeks.

Prevention/Treatment

Do not induce vomiting. A person exposed to VX should immediately don a respiratory mask. The person should be thoroughly decontaminated by washing with large amounts of water and soap, sodium carbonate or bleach. This should be done gently as scrubbing will increase absorption. Emergency personnel should administer antidote. The patient may need an IV or to be placed on a ventilator to restore breathing. If there are seizures, a sedative such as Valium may help. Because symptoms may take up to 18 hours to appear, the person should be kept in the emergency room.

Environmental Cleanup

Contaminated clothing should be removed, bagged and sealed. Because of VX's persistent characteristics, it is important to avoid secondary contamination from clothing, the ground, vegetation or equipment. Once VX dissipates, which can take several days, it is not a long-term threat to the environment.