by Prof. Michael Breadmore
This year, 2016, has seen two of the most devastating attacks on airports in history. Landside incidents in Brussels and Istanbul inflicted damage and incited terror through the exploitation of deficiencies in airport security that, while well known by those in the industry, have infrequently been targeted with such skill and devastation.
There are multiple layers of security at airports after (and in some places before) check-in that provide travellers with confidence that they are safe. But performing security prior to traditional security checkpoints, is more challenging. Simply moving screening to airport approaches and entrances prior to check-in is likely to simply create another location in which people collectively aggregate thereby providing an equally attractive target to what we currently experience. It seems apparent that security screening as it is currently done is unlikely to be a solution to this problem – but does a solution exist and is there a way that our significant development of detection technology can be exploited towards this end?
It is beyond a doubt that intelligence is the greatest weapon in the prevention of terrorist incidents, both at airports, and throughout the community in general. If performed correctly, there will be no public awareness that anything untoward may have occurred. Failure on the other hand, can have catastrophic consequences, and is often followed by criticism and blame. Of course, the capability to inflict damage goes hand-in-hand with intent, and identification through the source of capability is a very effective strategy. One possible approach is to detect unauthorised access to difficult-to-source ingredients (such as TNT), and this is one form of chemical intelligence that can, and is used to identify suspects. However this does not address terrorists obtaining chemicals to make homemade bombs that can be sourced from grocery, hardware and drug stores. Tracing the purchase and use of acetone, fertiliser and chlorine is not currently done, so we rely only on intelligence based on intent, and failing that, security at airports, to prevent an incident. The recent attacks have shown that when the perpetrator reaches the airport with both intent and capability, then it is likely to be too late to avoid disaster. We need to think about how to perform ‘security screening’ further away from the airport and the choke points that we currently have.
And that brings me to EMPHASIS – Explosive Material Production (Hidden) Agile Search and Intelligence System – a recently completed project funded through the European Community’s Seventh Framework Programme. This project brought together a consortium of research organisations, companies and government agencies to examine the potential of a broad scale urban monitoring system to chemically detect the ingredients used to make improvised explosive devices. The project aimed to detect explosives and precursors in the vapour phase, in sewage and on surfaces, such as door handles.
Underpinning EMPHASIS is the critical selection of suitable technology to provide complete coverage of materials that can be most easily used to make explosives at home, such as acetone. Inorganic explosive components such as ammonium, nitrate, chlorates and perchlorates, which were used in Bali, are not volatile, and are unlikely to be detected in air. However, such materials can potentially contaminate and be spread by contact with clothing and may end up in the sewage and storm-water systems. In the EMPHASIS project, particulates on surfaces were detected through stand-off laser spectroscopy detecting infrared or Raman backscattering; Vapour sensing of volatile explosives and precursors was performed using resonant Raman scattering and infra-red absorbance spectroscopy and sewage sensing was performed through a suite of individual ion selective electrodes. Each of these sensor nodes is connected in a network, and the data collected and analysed to determine whether further investigation is warranted.