VX Nerve Agent: A Deadly Weapon, Rarely Seen
HONG KONG — The Malaysian authorities said on Friday that Kim Jong-nam, the half brother of North Korea’s leader, had been killed by VX nerve agent applied to his face. The substance, listed as a chemical weapon, was kept for decades in the arsenals of many militaries, including that of the United States. But since the Chemical Weapons Convention came into force in 1997, most stockpiles globally have been destroyed.
香港——马来西亚当局周五表示，朝鲜领导人同父异母的哥哥金正男(Kim Jong-nam)是被抹在他脸上的VX神经毒剂毒死的。这种物质被列为化学武器，过去有几十年时间，美国等很多国家军队的武器库都存储过它。但是，自从《禁止化学武器公约》(Chemical WeaponsConvention)于1997年生效以来，全球各地存储的大多数VX神经毒剂已被销毁。
What is a nerve agent?
A nerve agent, sometimes called nerve gas, acts on the nervous system of an organism and prevents muscles from functioning properly. The substance is derived from organophosphate pesticides, and military officials had envisioned dispersing it over a wide area — using a specialized artillery shell or bomb, for instance — to kill or incapacitate enemy forces and make the affected area impossible to safely move through.
How does it kill you?
The VX molecule interferes with the way glands and muscles function by blocking an enzyme that allows them to relax. That causes muscles to clench uncontrollably and, eventually, prevents a victim from being able to breathe. The lethal dose for VX ranges from about 10 milligrams via skin contact to 25 to 30 milligrams if inhaled. Early symptoms can include pinprick pupils, runny nose, wheezing and muscle twitching. Death can occur anywhere from within a few minutes to hours, depending on the dose and the method of contact. 纽约时报中英文网 http://www.qqenglish.com
Are there any antidotes?
Injections of atropine, if administered quickly after exposure, can counteract the lethal effects of VX. The drug prevents VX from blocking the enzyme, allowing cells to resume functioning normally. Hospitals generally have atropine on hand; it is commonly used in much less drastic situations, like dilating pupils for eye exams. Anticonvulsive drugs like diazepam may also be administered. Military forces are often equipped with autoinjectors, which can be removed from a wrapper and used directly through clothing or protective gear in the event of an attack.
Has VX been used before?
Not in combat. In 1994 and 1995, the Japanese cult Aum Shinrikyo used homemade VX to poison three people, one of whom died. In the 1960s, testing of a nerve agent that may have been VX led to the accidental deaths of thousands of sheep in Utah. Syrian government forces are accused of using a related nerve agent, possibly sarin, against civilians in 2013.<-->纽约时报中英文网 http://www.qqenglish.com<-->
How detectable is VX?
In its purest form, VX is colorless, tasteless and odorless. But production often introduces small impurities, turning it light yellow or amber. It is slightly oily to the touch and is considered not very volatile, meaning it does not evaporate quickly. Its chemical makeup is easily detectable through testing, but if medical personnel are not expecting to encounter it, that testing may not occur. VX can also be delivered in “binary” form, meaning two relatively harmless compounds can be combined in the field to create the lethal nerve agent, which may have been the method used to kill Mr. Kim.
How do you make VX?
Very carefully. Many of the individual ingredients — sulfur, for instance — are easy to come by. Others, like hydrochloric acid gas, may require some hunting. Obtaining all of them would most likely draw the attention of some high-ranking law enforcement officials. Making VX is, essentially, a matter of having the right ingredients and gear like flasks, distillation equipment, aspirators and a desire to manufacture something deadly enough to kill you with a single misplaced drop.