UN inspectors gear up for a sarin-hunting expedition in Syria

By Ian Sample  /  The Guardian, LONDON

Tue, Aug 06, 2013 - Page 9

UN inspectors are to go to Syria as soon as possible to investigate alleged attacks employing chemicals weapons at three sites in the country.

The investigation was given the green light after a visit to Damascus late last month by Ake Sellstrom, head of the chemical weapons team, and UN High Representative for Disarmament Affairs Angela Kane.

“The team will depart for Syria as soon as practical and is preparing to depart within days,” Martin Nesirky, a UN spokesman, said on Thursday last week.

The breakthrough ends months of negotiations that began when the regime invited the UN to investigate an attack at Khan al-Assal, a village near Aleppo on March 19. The government and rebel forces blame each other for using chemical weapons in the attack.

Plans to send inspectors into Syria were put on hold soon after the initial invitation, when the UN’s request to visit other sites of alleged attacks was refused by Syrian President Bashar al-Assad’s government.

The UN Security Council has reports of 13 alleged chemical weapons attacks in Syria since civil war broke out in March 2011. The inspectors will visit Khan al-Assal, but the UN has not disclosed the other two sites.

UN Secretary-General Ban Ki-moon has previously called for an investigation in Homs, following reports of an attack in December last year.

The investigation will look only at whether chemical weapons have been used, not who used them. The US, Britain and France have already said that the nerve agent sarin has been used in the war; samples smuggled from Syria, with security services’ help, have been analyzed.

In June, US President Barack Obama’s administration moved to arm Syrian rebels, citing conclusive evidence that the regime had used sarin against the insurgents.

Under Sellstrom, a chemical weapons expert from Sweden, the UN has drawn together a team of interpreters and medics that will support inspectors from the Organisation for the Prohibition of Chemical Weapons (OPCW). The team faces a big challenge given the number of sites it is restricted to, the small amounts of nerve agent probably used and the time that has passed since some of the attacks.

“Some people say that it’s already too late, and I can definitely understand that,” one inspector said on condition of anonymity. “People are afraid of a result that’s neither positive or negative, but an inconclusive maybe.”

Ralf Trapp, a chemical weapons expert and former OPCW scientist, said an uncertain result was a fair concern.

“The problem with coming back and saying we didn’t find anything is that the allegations don’t go away. If you can prove someone used it the questions you ask change,” he said.

“Sarin is not something you pick up at the pharmacy. So you move on to who had access, and who can make it. Sarin is not hard to make, but it is extremely hard to make safely,” he said.

Despite the difficulties, the investigation is worthwhile, Trapp said. The UN team is independent, he said, and it would base its conclusions on a wealth of evidence that could be used in court.

“That’s not the case for a lot of what comes from the intelligence agencies,” he said.

The first task for the inspectors is to visit each site. Charles Duelfer, the former US chief weapons inspector, said officials could deter inspectors by emphasizing the dangers in an area.

“Once they’re on the ground, the government can use that as a tool, as a way of constraining [inspectors’] movement,” he said.

Another tactic of officials in the country, he said, was to assign minders to inspection teams, which could have a chilling effect on people being interviewed.

To build up a picture of events at any particular site inspectors will interview victims, witnesses, doctors and residents, some a fair distance from the scene. In a sarin attack, about 85 percent of the chemical agent misses its target; it ends up in the soil, or blowing over to other neighborhoods.

Sarin is colorless, odorless and tasteless. It causes a range of symptoms, from respiratory failure, eye irritation, and blurred vision to constricted pupils and drooling. People foam at the mouth when forced to breathe through massive secretions of fluid in their lungs. The expelled foam can be tinged pink with blood.

Weaponized sarin is usually dispersed though an explosive device that sprays droplets fine enough to be inhaled deep into the lungs, though the agent enters through the skin and eyes too. In the body, sarin blocks an enzyme, causing nerves to fire constantly. A lethal dose can kill in one to 10 minutes. Those people who survive the first 15 to 20 minutes usually live.

Trapp said that what witnesses failed to say could matter as much as the details they described.

“There are certain things you’ll see when chemical weapons are used, and if people tell you stories that don’t include these things, you start to wonder what really happened,” he said.

For example, some people may be killed almost instantly, but those who go to help can become contaminated too. Many of these will then suffer and they can die. This was found out after the 1995 sarin attacks on the Tokyo subway by the Aum Shinrikyo cult.

Footage of suspected attacks in Syria shows victims taken to hospital without being stripped of their clothes or being isolated from others.

“These people still had their clothing on, so if there was a sarin attack they would be contaminated. Half the people who helped them would be dead, or would have picked up enough to be sick themselves,” Trapp said.

The reports that inspectors derive from people on the scene may be confused and inconsistent. For example, sarin can be mixed with other agents, such as military grade teargas, and people exposed might smell pungent fumes. The symptoms they experience may differ according to the agent. Ultimately, chemical and biological tests are needed to confirm which agent has been used.

Interviews make up only one strand of evidence. Another comes from direct tests on soil and medical samples taken from victims. Sarin is volatile and breaks down quickly in contact with moisture. The process is speeded up by UV rays in sunlight, rain, humidity and wind. However, traces of sarin and other agents can still be found years after an attack.

The highest concentration of nerve agent will be where the canister, shell or missile lands. In most cases, the impact craters will be hard to find, but not in other circumstances. In May, the mother of a family in the northern town of Saraqeb was killed after a device landed in her garden. Impact sites can retain contaminated soil and fragments of munitions.

In 1992, Alastair Hay, an environmental toxicologist at Leeds University, worked with Human Rights Watch to investigate suspected chemical weapons attacks, four years earlier in Kurdistan. He took soil samples from four impact craters, and found a fragment of a bomb in one.

Hay’s evidence was passed for analysis to Porton Down, Britain’s chemical warfare laboratory in Wiltshire. There, a scientist noticed a flake of paint on the metal shard. It was found that the material behind it tested positive for sarin.

The OPCW has portable equipment for running tests in the field, but Sellstrom’s team will collect samples and send them to laboratories that make up the OPCW’s global network. One is Porton Down. Other labs are in China, Russia, Japan and the US. Samples sent for analysis are worthless if there is any possibility of their having been tampered with, so they are all closely guarded.

In April, the White House said the “chain of custody” of samples that the US had tested was unclear, a problem that lay behind its statement in which said it believed with “varying levels of confidence” that Syria had used the weapons.

Inspectors are unlikely to find sarin in the soil long after an attack, but traces of its breakdown products might show up. Sarin first breaks down into a chemical called isopropyl methylphosphonic acid (IMPA), generally regarded as proof positive.

“There is no other nerve agent containing the structural features of IMPA that is known to be mass-produced, weaponized or fielded,” one serving chemical weapons inspector said.

The inspectors will also test medical sample for traces of IMPA.

“My sense is that it’s probably worth [the UN] going in. They’d be the only party who really have an interest in the truth,” Duelfer said. “If they do this, it’s a deterrent, and that is a supporting element of trying to keep chemical weapons under control, because of the threat that it could get into the wrong hands.”