Chemical Network Algorithms for the Risk Assessment and Management of Chemical Threats

摘要

Among the millions of known chemical substances, there exist nerve gases, toxic agents, explosives, and many other dangerous compounds. Once proprietary information held by a select few, the synthetic methods leading to these chemical weapons (CWs) have nowadays become readily available, and the internet is home to entire message boards devoted to the nuances of creating nerve gases, such as sarin, VX, and tabun. Although it is sometimes argued that such amateur activities are not worrisome (a large proportion of the poorly trained and ill-equipped terrorists die trying to synthesize nerve gasses), the 1995 attack on the Tokyo metro using sarin gas home-made on the preceding afternoon from commercially available reagents suggests a more cautionary attitude is required. Recognizing the potential threat, the regulatory governmental agencies put forth their best efforts to ban both hazardous chemicals and their immediate precursors. Yet, as we demonstrate herein using the network-theoretical approach, these efforts are only partially effective, and a range of extremely dangerous substances can still be easily made from unregulated and unmonitored reagents. The challenge of identifying and regulating all possible pathways leading to CWs is simply beyond human cognition; it is only through computational searches spanning the entire network of chemical knowledge that we can appropriately identify, rank according to the potential ill-intent (using the elements of game theory), and ultimately eliminate unregulated syntheses of CWs. Network analyses are an unprecedented and powerful method for a watchful management of chemical threats.