On April 7, images and video footage of dozens of dead Syrian children and adults foaming at the mouths, or injured and struggling to breathe, once again began circulating around the world. The latest chemical-weapon attack, targeting the rebel-held suburb of Douma east of Damascus, reportedly caused at least forty-two deaths and injured five hundred, though some sources claim seventy deaths or more.
The Violations Documentation Center, a human-rights monitoring group, has published a timeline of the events on April 7, beginning at noon with a guided-missile strike and barrel-bomb attack on a Red Crescent center in Douma, which destroyed its last remaining ambulances. Then at 4 p.m., an air attack apparently delivered the first chemical strike in the vicinity of the Saada Bakery. Bakeries have been popular targets for Russian and Syrian government warplanes, as they assure the food supply of civilians in rebel-held areas.
The attack apparently caused fifteen to twenty-five deaths, particularly among families in enclosed spaces (bomb shelters or basements) who passed out or died from suffocation as heavier-than-air gases accumulated there. One extremely graphic and disturbing video depicts the huddled corpses of entire families, including several babies, dead with foam pouring out of their mouths and noses.
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A second strike landed at 7:30 p.m. around Martyr’s Square, killing an estimated twenty more and resulting in five hundred more patients being brought to a local medical center. Some rescuers attempting to aid survivors also suffered breathing difficulties. You can see slightly less graphic footage of a local clinic being overwhelmed by patients, including young children, here.
Victims of the attack reportedly reeked of chlorine. Two Syrian government Mi-8 “Hip” transport helicopters were reported by an aviation-monitoring group operating over the area around the time of the attack. Mi-8s have previously been observed dropping chlorine canisters on rebel targets, which release greenish-yellow gas on impact.
Additionally, two yellow canisters used to deploy chlorine gas were recorded by multiple sources at the site of the attack in Douma; you can see one of them in this video . Some of the civilian casualties and the two canisters have been geolocated in an investigative report by Bellingcat . The open-source investigation site argues that these support evidence of a chlorine attack.
However, there is good reason to suspect that chlorine was not the only chemical agent deployed in Douma on April 7.
First Lethal Chemical Weapon Used on the Battlefield
Chlorine gas was the first lethal chemical weapon to see wide-scale use on the modern battlefield, when German forces deployed gas projectors against French colonial troops in the Second Battle of Ypres during World War I. The weaponization of chlorine was carried out at the suggestion of future Nobel Prize–winning chemist Fritz Haber; shortly after the battle, Haber’s pacifist wife, Clara Immerwahr, commited suicide in apparent protest.
The gas irritates the lungs and causes the mucous membranes to fill with liquid, making breathing difficult and potentially leading to suffocation. The chlorine also mixes with water in the eyes and lungs to form hydrochloric acid, potentially causing blindness and permanent lung damage.
However, chlorine gas generally harms far more people than it kills because it requires comparatively high concentrations (nineteen thousand milligrams per cubic meter) and prolonged exposure to achieve lethal effect, usually conditions that prey on immobilized victims (sleeping or injured), or those on lower ground and enclosed spaces. Children and the elderly are likewise more susceptible than adults.
In World War I, all sides rapidly deployed countermeasures such as gas masks against chlorine gas, and moved on to deadlier chemical weapons. Nerve agents , first developed by the Nazis during World War II, are dramatically more lethal than chlorine; just thirty-five milligrams of sarin per cubic meter will kill. It is estimated over a thousand Syrians were killed in a single sarin gas attack on Ghouta in 2013.
Since 2012, Syrian military helicopters have “systematically and repeatedly” ( according to the Organization for Prohibition of Chemical Weapons) dropped chlorine gas on rebel-held towns and urban neighborhoods; more than two dozen attacks have been recorded. These attacks continued even after Syria supposedly disposed of its chemical-weapons stocks to avoid international retribution for the Ghouta sarin attack as part of a deal brokered by Russia.
The chlorine gas attacks also continued through 2017 and early 2018 , even after the United States launched a missile strike on Syria as punishment for its deployment of air-dropped nerve agents on the rebel-held town of Khan Sheikhoun, which killed around seventy.
These attacks are an indiscriminate terror tactic directed more at the civilian population than armed fighters, intended to make daily life in rebel-held communities as intolerable as possible so as to provoke an exodus to government-controlled territory. ISIS has also deployed chlorine and mustard gas (a blistering agent) in Iraq and Syria, and a Syrian rebel group has been implicated in a chlorine attack on a Kurdish community.