(concernant le novitchok, j'ai toujours pas compris si la dégradation dans l'environnement était rapide ou pas, j'avais cru comprendre que c'était le cas, j'ai lu le contraire, et apparemment il semblerait que ce soit relativement persistant mais que la dangerosité baisse rapidement — http://www.opex360.com/2018/07/05/deux-britanniques-ont-ete-exposes-meme-poison-utilise-contre-colonel-russe-serguei-skripal/ )

https://www.opcw.org/news/article/opcw-issues-fact-finding-mission-reports-on-chemical-weapons-use-allegations-in-douma-syria-in-2018-and-in-al-hamadaniya-and-karm-al-tarrab-in-2016/
The results show that no organophosphorous nerve agents or their degradation products were detected in the environmental samples or in the plasma samples taken from alleged casualties. Along with explosive residues, various chlorinated organic chemicals were found in samples from two sites, for which there is full chain of custody. Work by the team to establish the significance of these results is on-going. The FFM team will continue its work to draw final conclusions.