Syria Chemical Attack: This Is What Happens When You're Exposed to a Deadly Nerve Agent

Video from local aid worker of victims with non-responsive pupils seems to suggest 58 people killed by Assad forces in Idlib died from exposure to Sarin, the gas that wreaked havoc in Tokyo in 1995.

A volunteer for the Syrian "White Helmets" breathing oxygen after the chemical weapons attack in Idlib on Tuesday.
A volunteer for the Syrian "White Helmets" breathing oxygen after the chemical weapons attack in Idlib on Tuesday. Ammar Abdullah/Reuters

Have the forces of beleaguered Syrian president Bashar Assad, and/or possibly Russian forces, been using nerve gas on Syrian civilians? Media sources affiliated with the Assad regime deny it, but the U.K.-based Syrian Observatory for Human Rights claims that 58 people were killed by gas in an attack near Idlib on Tuesday.

>> Assad's chemical attack in Syria: Two failures and two lessons to consider | Analysis <<

At least one self-proclaimed aid worker in northern Syria, Dr. Shajul Islam, took to Twitter  to show pictures of victims with tell-tale signs of attack with sarin, an insecticide that was developed into a nerve gas.

Indeed, a video uploaded by Dr. Islam shows a woman's pupils nonresponsive to light being shone into her eyes, which could be an indicator of sarin use.

One problem with sarin is that it has no odor or taste. We don't even know it's there until our bodies react.

Absorbed through any exposure, to the skin or membranes or lungs, or mixed into water, sarin does not inevitably kill, but its victims suffer badly until its effects wear off, as they lose control of their smooth muscles – the involuntary tissue that supports our organs such as the stomach, intestine, and bladder, and our blood vessels, too.

What sarin causes our bodies to do is void without cease. The gas molecules block enzymes that cause our nerves to stop firing after stimulation.

Reaction to the gaseous form is practically immediate, and violent: we immediately, and violently, void our waste, both urine and feces. We sweat and vomit. Our mouths drool and our noses drip uncontrollably, and our eyes tear and leak – not that we can see ourselves doing this in the mirror, because our vision blurs as our pupils contract.

Sarin can also cause mental confusion, and at high doses, it can be deadly, in the space of minutes. "Mildly exposed people usually recover completely. Severely exposed people are less likely to survive," the Center for Disease Control observes.

Assad's forces have been accused of using chemical agents before, including in Aleppo and Homs (and have accused the other side of using them too). Confirmed use of sarin specifically in modern history remains rare. On March 20, 1995, members of the religious cult Aum Shinrikyo released sarin on packed subways in Tokyo, killing 13 and injuring over 6,000 people. Authorities said the death toll would have been much higher if the cultists had been more efficient at releasing the nerve agent.

Surviving a sarin attack does not necessarily mean restoration of health. No less to the point, survivors of the attack in Japan still say they suffer from impaired vision and fatigue.

FILE - Subway passengers affected by sarin gas planted in central Tokyo subways are carried into St. Luke's International Hospital in Tokyo in March 1995.
Chiaki Tsukumo/AP