In the hour before and after Kim Jong Nam was supposed to fly from Malaysia to Macau at 10 a.m. on Feb. 13, nearly 200 flights were scheduled to fly to or from Kuala Lumpur.

Flights from nearby Singapore, more than a dozen. Arrivals from airports all over Southeast Asia. Flights to Qatar, Australia, Japan and Taiwan. A flight from Alaska and two flights to London’s Heathrow Airport. Some 200 flights moving thousands of people across the globe.

Kim didn’t make his flight to Macau. Before his plane departed, a young woman approached him from behind and apparently swiped his face with a cloth. That cloth may have contained the nerve toxin VX, according to Malaysian authorities. Kim, the half brother of North Korean leader Kim Jong Un, died at Kuala Lumpur International Airport.

But consider all of the people getting ready for some of those 199 flights. Each of them was possibly within 100 yards of a rare, deadly nerve agent that might have made its way through the airport until the moment that it was swiped on Kim’s face. Depending on how the VX got onto that cloth, and where, and how careful the two women assassins were in applying and transporting it, that danger could remain.

‘YOU’RE GONE’

Cindy Vestergaard is senior associate at the Stimson Center, a national security think tank in Washington, D.C. She spoke by phone Friday from Australia, where she is a visiting fellow at the Center for International Studies at the University of Sydney.”VX is highly toxic. It just takes a drop, and that’s it,” she said. “Unless you have an antidote, you’re gone.”

Vestergaard pointed out the obvious risk posed by an assassin carrying a cloth with VX through an airport.

“We watched her walk across one of the terminals. She would have had to have carried this cloth with her. Even if she had gloves on, it would have dispersed somehow, somewhere,” she said. “Onto her, maybe onto someone else if she would have brushed against someone. Something would have dropped, onto a shoe, onto a suitcase.” Wherever she doused the cloth might be contaminated, Vestergaard said. “Even to open the vial and carry a vial” risks contaminating the environment.

The toxin “can remain on material, equipment and terrain for long periods,” the Organisation for the Prohibition of Chemical Weapons says on its website. “All nerve agents in pure state are colorless liquids. Their volatility varies widely. The consistency of VX may be likened to an involatile oil and is therefore classified as belonging to the group of persistent CW agents.” A suitcase sitting on the tarmac in the rain could have a drop of VX washed off, for example, but in other places it could linger for some time.

VICTIM SUFFOCATES

It works quickly. “Its effect is mainly through direct contact with the skin,” the OPCW says. Poisoning using a gas leads to a more rapid effect than through contact with the skin, because in the latter case it can take 20 to 30 minutes for the agent to reach deeper blood vessels.

When it does, however, the effect is to essentially paralyze respiratory functions – the victim suffocates. Because persistent agents don’t evaporate, it requires a smaller amount to kill. In the case of VX, the OPCW says, the amount of the agent required to have a fatal effect in 50 percent of victims is 10 milligrams.

An amount the size of three snowflakes. One-ninth of a grain of sand.

“I think the investigation now – if this is confirmed to be nerve agent – is going to be massive because it is in an airport,” Vestergaard said.

“You’re going to have to track those people that were in that area. What planes were being checked in. You have to have a hotline, if anyone gets sick. All those people will have to be tested.”

On Friday, the authority in charge of the airport released a statement indicating that there were “no anomalies” among those who sought medical care in the airport’s clinic.

What’s more, Malaysia Airports said, the airport is cleaned six times a day and “the cleaning staff are in good health.” That said, the terminal where Kim was murdered – KLIA2 – was to be swept Saturday night for indicators of the presence of VX, according to Reuters.