グータ化学攻撃
Blood and urine samples from the same patients were found positive for sarin and sarin signatures.
The 7th Report of the Independent International Commission of Inquiry on the Syrian Arab Republic, a different group than the UN fact-finding mission, stated the sarin used in the Ghouta attack bore the "same unique hallmarks" as the sarin used in the Khan al-Assal attack. The report, dated 12 February 2014, also indicated that the perpetrators likely had access to the chemical weapons stockpile of the Syrian military. These conclusions were based on the fact-finding mission's evidence, as the Commission of Inquiry did not conduct its own investigation of either chemical attack.
The continuous fighting has severely limited the quality of medical care for injured survivors of the attack. A month after the attack, approximately 450 survivors still required medical attention for lingering symptoms such as respiratory and vision problems. By early October 2013, the 13,000 residents of Moadhamiya, one of the places targeted in the August attack, had been surrounded by pro-government forces and under siege for five months. Severe malnourishment and medical emergencies become pressing as all supply lines had stopped. Care for chronic symptoms of sarin exposure had become "just one among a sea of concerns."
As countries such as the United States and the United Kingdom debated their response to the attacks, they encountered significant popular and legislative resistance to military intervention. In particular, British Prime Minister David Cameron's request to the House of Commons to use military force was declined by a 285–272 margin. UK government policy subsequently focused on providing humanitarian assistance inside Syria and to refugees in neighboring countries.
Within a month of the attacks, Syria agreed to join the Chemical Weapons Convention and allow all its stockpiles to be destroyed. The destruction began under OPCW supervision on 6 October 2013. On 23 June 2014, the last shipment of Syria's declared chemical weapons was shipped out of the country for destruction.  By 18 August 2014, all toxic chemicals were destroyed aboard the US naval vessel MV Cape Ray.
Nine months after the attack, there is evidence that mothers from the affected areas are giving birth to children with defects and as stillborn.
Syrian human rights lawyer Razan Zaitouneh, who was present in Eastern Ghouta, stated, "Hours [after the shelling], we started to visit the medical points in Ghouta to where injured were removed, and we couldn't believe our eyes. I haven't seen such death in my whole life. People were lying on the ground in hallways, on roadsides, in hundreds." Several medics working in Ghouta reported the administration of large quantities of atropine, a common antidote for nerve agent toxicity, to treat victims.
Doctors Without Borders said the three hospitals it supports in Eastern Ghouta reported receiving roughly 3,600 patients with "neurotoxic symptoms" over less than three hours during the early morning of 21 August. Of those, 355 died. The Local Coordination Committees of Syria claimed that of the 1,338 victims, 1,000 were in Zamalka, of which 600 bodies were transferred to medical points in other towns and 400 remained at a Zamalka medical center. Some of the fatalities were rebel fighters. The deadliness of the attack is believed to have been increased due to civilians reacting to the chemical attack as if it was typical government bombardment. For conventional artillery and rocket attacks, residents usually went to the basements of buildings, where in this case the heavier-than-air sarin sank into these below-ground, poorly ventilated areas. Some of the victims died while sleeping.
Abu Omar of the Free Syrian Army told The Guardian that the rockets involved in the attack were unusual because "you could hear the sound of the rocket in the air but you could not hear any sound of explosion" and no obvious damage to buildings occurred. Human Rights Watch's witnesses reported "symptoms and delivery methods consistent with the use of chemical nerve agents." Activists and local residents contacted by The Guardian said that "the remains of 20 rockets [thought to have been carrying neurotoxic gas] were found in the affected areas. Many [remained] mostly intact, suggesting that they did not detonate on impact and potentially dispersed gas before hitting the ground."
Doctors Without Borders also reported seeing a "large number of victims arriving with symptoms including convulsions, excessive saliva, pinpoint pupils, blurred vision and respiratory distress." Symptoms reported by Ghouta residents and doctors to Human Rights Watch included "suffocation, muscle spasms and frothing at the mouth."
Witness statements to The Guardian about symptoms included "people who were sleeping in their homes [who] died in their beds," headaches and nausea, "foam coming out of [victims'] mouths and noses," a "smell something like vinegar and rotten eggs," suffocation, "bodies [that] were turning blue," a "smell like cooking gas" and redness and itching of the eyes. Richard Spencer of The Telegraph summarised witness statements, stating, "The poison ... may have killed hundreds, but it has left twitching, fainting, confused but compelling survivors."
On 22 August, the Center for Documentation of Violations in Syria published numerous testimonies. It summarised doctors' and paramedics' descriptions of the symptoms as "vomiting, foamy salivation, severe agitation, [pinpoint] pupils, redness of the eyes, dyspnea, neurological convulsions, respiratory and heart failure, blood out of the nose and mouth and, in some cases, hallucinations and memory loss".
Dr. Amesh Adalja, a senior associate for the Center for Biosecurity at the University of Pittsburgh Medical Center, said the reported symptoms are a textbook case of nerve-agent poisoning.
Médecins Sans Frontières Director of Operations Bart Janssens stated that MSF "can neither scientifically confirm the cause of these symptoms nor establish who is responsible for the attack. However, the reported symptoms of the patients, in addition to the epidemiological pattern of the events – characterised by the massive influx of patients in a short period of time, the origin of the patients, and the contamination of medical and first aid workers – strongly indicate mass exposure to a neurotoxic agent."
Gwyn Winfield, Editorial Director at CBRNe World, analysed some videos from the day of the attack and wrote on the magazine's website: "It is difficult to define [an] agent by the signs and symptoms. Clearly respiratory distress, some nerve spasms and a half hearted washdown (involving water and bare hands?!), but it could equally be a riot control agent as a [chemical warfare agent]."
Human Rights Watch reported that two types of rockets were used: in Western Ghouta, a 140mm rocket made in the Soviet Union in 1967 and exported to Syria; and in Eastern Ghouta, a 330mm rocket of unknown origin. HRW also reported that at the time of the attack, Syrian rebels were not known to be in possession of the rockets used.
Seymour Hersh has suggested that the 330mm rockets may have been produced locally, and with a limited range. Blogger Eliot Higgins has looked at the munitions linked to the attack and analysed footage of the putative launchers inside government territory.
According to a study published in January 2014 by Theodore Postol and Richard Lloyd, of the Massachusetts Institute of Technology, the rockets used in the attack had a range of about two kilometers, indicating the munitions could not have been fired from the 'heart' or from the Eastern edge of the Syrian Government Controlled Area shown in the Intelligence Map published by the White House on 30 August 2013. A response from Higgins and Kaszeta included an observation that the Russian-language news site ANNA News had posted videos showing a Syrian government military operation running from June to August 2013 to clear positions between Jobar and Qaboun, a strip of land about 2 km away from the 21 August impact sites. MIT Professor Theodore Postol contacted Dan Kaszeta and asked him how he came to the conclusion that Hexamine was the "smoking gun" regarding the alleged culpability of the Syrian Government. Åke Sellström told Postol that indeed "the presence of hexamine may mean that this substance was used as scavenger for protons when producing sarin" but that it was a common substance and not conclusive evidence implicating the Syrian government.
Many of the munitions and their fragments had been moved; however, in two cases, the UN could identify the likely launch azimuths. Triangulating rocket trajectories suggests that the origin of the attack may have been within government or rebel-held territory. Consideration of missile ranges influences calculations as to whether rockets originated from the government or rebel-held regions.
Two purported intercepts of communications that appeared to implicate the Syrian government received prominent media coverage. One was a phone call allegedly between Syrian officials which Israel's Unit 8200 was said to have intercepted and passed to the US. The other was a phone call which the German Bundesnachrichtendienst said it had intercepted, between a high-ranking representative of Hezbollah and the Iranian embassy, in which the purported Hezbollah official said that poison gas had been used and that Assad's order to attack with chemical weapons had been a strategic error.
On 29 August the Associated Press reported that, according to two U.S. intelligence officials and two other U.S. officials, the U.S. intercept was a conversation between "low-level" Syrian officials with no direct link to the upper echelons of the government or military.
The Bild am Sonntag newspaper subsequently reported that German intelligence indicated that Assad had likely not ordered the attacks. According to Bild, "intelligence interception specialists" relying on communications intercepted by the German vessel Oker said that Syrian military commanders had repeatedly been asking permission to launch chemical attacks for around four months, with permission always being denied from the presidential palace. The sources concluded that 21 August attack had probably not been approved by Bashar al-Assad.
Murad Abu Bilal, Khaled Naddaf and other Center for Documentation of Violations in Syria and Local Coordination Committees of Syria (LCC) media staff went to Zamalka soon after the attacks to film and obtain other documentary evidence. Almost all the journalists died from inhalation of the neurotoxins, except Murad Abu Bilal, who was the only Zamalka LCC media member to survive. The videos were published on YouTube, attracting world-wide media attention.
Experts who have analysed the first video said it shows the strongest evidence yet consistent with the use of a lethal toxic agent. Visible symptoms reportedly included rolling eyes, foaming at the mouth, and tremors. There was at least one image of a child suffering miosis, the pin-point pupil effect associated with the nerve agent Sarin, a powerful neurotoxin reportedly used before in Syria. Ralph Trapp, a former scientist at the Organisation for the Prohibition of Chemical Weapons, said the footage showed what a chemical weapons attack on a civilian area would look like, and went on to note "This is one of the first videos I've seen from Syria where the numbers start to make sense. If you have a gas attack you would expect large numbers of people, children and adults, to be affected, particularly if it's in a built-up area."