More than one hundred years after the first massive chemical attack, chemical warfare has lost none of its horror: as recently as on 4 April 2017, the town of Khan Shaykhun in western Syria suffered a severe chemical attack with nerve gases including sarin: more than 70 victims were killed and hundreds injured. The pictures of the dead children of Khan Shaykhun moved the world and led to an US airstrike against Syrian government forces. The Khan Shaykhun attack was the deadliest use of nerve gas in Syria since the 2013 chemical attack on Ghouta, a suburb of Damascus. The death toll then ranged from hundreds to thousands. Both towns had been held by rebel forces at the time of the attacks.
This horrific event in August 2013 set in motion a massive train of events: First, the US and French governments seriously considered airstrikes against Syrian government forces even then. Next, with the help of Russian diplomacy, an UN resolution was adopted that demanded of the Syrian government to declare its entire chemical weapons arsenal and cooperate in its destruction. Finally in October 2013, teams from the Organization for the Prohibition of Chemical Weapons (OPCW) went to Syria and destroyed all declared Syrian chemical weapons, with the help of several western governments plus Russia and China, by mid-2014.
Here’s the exact sequence of events: on 1 October 2013, the OPCW began its preliminary inspections of Syria’s chemical weapons arsenal, the actual destruction operation began on 6 October – and on 11 October, the OPCW was awarded the 2013 Nobel Peace Prize by the Oslo Nobel Committee “for its extensive efforts to eliminate chemical weapons”, mentioning the “recent events in Syria” explicitly. The OPCW was founded to enforce the Chemical Weapons Convention that came into force in April 1997 “to eliminate the possibility of developing, producing, using, stockpiling or transferring these dreadful weapons forever,“ as the OPCW stated in 2016. It is not a United Nations organisation, but it closely cooperates with the UN.
As later attacks with nerve agents made clear: the Syrian government either hadn’t declared all its stockpiles in 2013, or new agents had arrived in Syria in the meantime. Already in July 2016, the Director General Ahmet Üzümcü issued a written statement casting doubt on the Syrian government’s stockpile declaration, which had just undergone some amendments. He went on: “In particular, the lack of original documentation and access to senior leadership within the Syrian chemical weapons programme has precluded the secretariat from understanding the full scope of activities. In addition, some explanations were not scientifically or technically plausible.”
After the April 2017 attack, the OPCW stated that their own analyses “indicate exposure to sarin or a sarin-like substance,” and that “the analytical results already obtained are incontrovertible.” The OPCW is prepared to send inspectors back to Syria, but the current security situation doesn’t allow their return: In May 2014, one of four inspection vehicles was hit by an explosive charge and the mission was aborted. Government and rebel troops blamed each other.
Scientists are not only helping the OPCW to destroy chemical weapons, they are also working on new therapies against nerve agents post-exposure. There are some active substances against nerve gas poisoning already, but they can have serious side effect: an infusions of pralidoxime for instance can lead to respiratory or cardiac arrest if given too quickly. However, in the treatment of nerve agent poisoning speed is of essence to prevent asphyxiation. Now enzymes are known to act very fast (the fastest can perform a million reactions per second – and that’s exactly what’s needed in case of nerve gas poisoning: hundreds of nerve agent molecules need to be broken down each second. So researchers started looking for enzymes to ‚hydrolyse‘ sarin, i.e., to break it down in water.
In the lab or on destruction sites, sarin is easily hydrolysed, but only under high temperatures that cannot be applied to the human body. Finally, the researchers found their enzymes in an unlikely place: in fields that had been treated with pesticides similar to nerve agents. Sarin originally had been invented as a pesticide, so it’s not surprising that similar chemicals are used in agriculture. Now some soil bacteria that had been sprayed with these substances repeatedly in large quantities found a strategy to hydrolyse these agents. A proof-of-concept study in Germany and Israel with anaesthesized guinea pigs showed that all animals survived after first being poisoned with a nerve agent and then being treated with the new, improved therapy based on soil bacteria enzymes.
The first ever massive nerve gas attack against humans happened during World War I. Even one hundred years later, the reports on the slow death from chlorine, mustard or phosgene gas are heartbreaking to read. This particular horror of the trenches made blatantly obvious that this was not only the first global war, but also the first total war: a war against soldiers and civilians alike, disregarding international law. And indeed, many civilians suffered from gas attacks when the wind blew deadly clouds into their villages.
The use of chemical weapons in war started in 1914 with small amounts of tear gas used by the French and German army. But as of 1915, the German side used large amounts of chlorine gas against enemy troops, both on the western and eastern front. The Entente governments claimed that these attacks were a violation of the Hague Declaration against the use of ‚asphyxiating poisonous gases‘, but the Germans argued that the Hague treaty had only banned chemical shells and not gas projectors – that’s actually splitting hairs, because gas projectors were just as deadly (and both sides used gas shells later on in the war).
The first large-scale chemical attack was launched on April 22, 1915 by the German troops in Ypres, Belgium, against Canadian and French colonial troops. As described by author Denis Winter, dying of asphyxiation after a chemical attack could take up to 48 hours. The survivors were often blinded for life and also had to live with severely damaged lungs. The Ypres chlorine gas attack had been planned by later Nobel Laureate Fritz Haber – while his wife Clara Immerwahr, the first woman ever to receive a doctorate in chemistry in Germany, became a staunch pacifist. After the Ypres attack, she killed herself with her husband’s service pistol. He immediately set off to the eastern front to coordinate the next attack.
As we have seen, the history of chemical weapons is a history of tragedies. Thanks to the OPCW, 90 percent of the world’s – declared – chemical weapons stockpiles have now been destroyed.
Ahmet Üzümcü, the OPCW Director General, will take part in the 2017 Lindau Nobel Laureate Meeting, and he will participate in the panel discussion ‚Ethics in Science‘ on Friday, 30 June on Mainau Island in Lake Constance.