CBRNe is an all-encompassing term for weapons employed by terrorists that can inflict not only mass destruction, but also widespread illness and disruption of civilian life or infrastructure.
The acronym has changed over the years as new threats have entered the terrorist arsenal, with the current version standing for chemical, biological, radiological (dirty bombs), nuclear and (improvised) explosives.
Recent military programmes have seen the development of sophisticated detection and countermeasure technology that can distinguish risk factors in increasingly tiny amounts and at a greater, safer distance. In the light of the Sarin nerve gas attack on the Tokyo metro system and the anthrax attacks in the USA following the 9/11 attacks, these have been adapted into effective protective measures for high-risk areas including city centres, airports and events arenas.
New York's 'Ring of Steel'
In August 2011, the New York Police Department (NYPD) released details of a US$2 million security network designed to make the area surrounding lower Manhattan the safest business district in the world. Combining video surveillance with CBRNE detection, the system is designed to prepare the city for any eventuality.
Named after a similar set of defences in London and partly developed by Lockheed Martin, the 'Ring of Steel' project built on an existing base of 500 cameras to a total of 3,000 by the tenth anniversary of 9/11. More than 400 are deployed at key sites alone, including Ground Zero, the Rockefeller Center and the train stations Grand Central and Penn Station.
As well as static sites, CCTV is increasingly being used on public transport. According to Police Commissioner Raymond Kelly, Ring of Steel technology has helped police officers arrest an estimated 100 criminals in the subways over the past eight months.
The feeds are scrutinised by human operators and an artificial intelligence system which can identify suspect activity by searching for objects of a specific size, shape and colour, and zoom in on an area of interest. Data is fed to a command centre via a single high-bandwidth fibre-optic network.
Video data is supported with a network of sensors to detect CBRNE threats from minute traces in the air. Operators will monitor all the incoming data and wirelessly issue a real-time alert if readings indicate the threat of a dirty bomb.
Despite concerns similar to those expressed in London of a 'surveillance society', there has been very little criticism of New York's Ring of Steel. "There's very little opposition. People believe the world has changed as a result of September 11th," said Kelly.
As terrorists wise up to the modern detection systems that could stop them carrying out directly fatal atrocities, they may look towards more insidious approaches, such as introducing substances in such tiny quantities that cannot be easily detected but build up to fatal levels in the body.
In one project designed to intervene at an early stage, the US Air Force (USAF) is seeking an implantable sensor that can detect very low levels of harmful biological or chemical substances in the wearer's blood or saliva in real time.
To date, detectors have only been able to sense the presence of sufficient substances to cause immediate harm. However, low levels of acute or chronic exposure can often go undetected until signs of illness appear, when it is too late to remove the subject from harm.
The USAF solicitation seeks broad-based biosensor technology that would sense potential threats from quantities of substance in the body of the wearer, undetectable by current sensors.
The USAF believes the solution lies in nano-scale biomolecular switches, which can detect target chemicals in biological samples in real time, as a solution. Previous research has shown they can be adapted to respond to a variety of stimuli, in this case the various chemical and biological substances which threaten the wellbeing of combatants. To date, they have not been applied to sensors that can monitor prolonged or repeated exposure to biological or chemical warfare agents in the living body.
The USAF wants the nanoparticle-based system to be implanted into the body and remain in an 'off' state until either chronic or acute exposure to target substances causes a change in the cells. The bimolecular switch could then be used to raise an alert.
One of the biggest challenges of the solicitation could be the requirement that these sensors should be able to detect changes caused by unknown threats as well as known ones. This would suggest they would seek certain chemical changes in the body that occur on exposure to different toxic threats, whatever the actual substance used.
As the attacks in Mumbai in 2008 and Norway in 2011 demonstrated, terrorists are circumventing detection using a combination of bombs and firearms.
These have informed new approaches, including the introduction of shot location technology originally developed to pinpoint snipers on the battlefield, now installed in several cities worldwide.
The UK's second-largest city Birmingham was a recent adopter of the technology after a number of shooting crimes went unsolved when witnesses either failed to step forward or witness evidence of the point where the shot was fired from was unreliable as it echoed off buildings.
The gunshot location system (GLS), manufactured by US gunshot and explosion location specialist ShotSpotter, uses audio sensors located throughout the northwest of the city to recognise gunshots from up to two miles away. Using acoustic triangulation, readings from three sensors are used to accurately calculate the origin of the shot. This is transmitted to a command and control centre within seconds and police can be dispatched to the scene using GPS.
The system can tell how many guns have been fired, distinguish gunfire from similar noises such as a car backfiring, as well as even tell whether a gun has been fired from a moving car and, if so, what direction it is travelling in.
The £135,000 system was funded by the Safer Birmingham project, a collaboration between West Midlands Police, Birmingham City Council and West Midlands Fire Service, among others.
Prior to the Birmingham project, ShotSpotter GLS had already been installed in a number of US cities and recordings from the system have been used to help convict criminals in cases where shots were fired.
The London Olympic and Paralympic Games is one such potential target, and CBRNe defence forms a key part of event security. The budget recently doubled to an estimated GBP £1bn out of the event's total GBP £9.3bn budget.
Responsibility for Emergency Procedures, Business Continuity and the strategic link with London Resilience falls under the auspices of the senior office of the Metropolitan Police Service.
The Association of Chief Police Officers (ACPO) has a dedicated project devoted to looking at potential CBRNe requirements as part of the overall risk assessment for the event, but for security reasons are unable to provide any details. They did however emphasise that no greater weight is being placed on the CBRNe issue than on any other part of security planning for the Olympics.
Staying a step ahead
Some of the most devastating terrorist attacks in recent years had the horrifying effect they did because they employed a form of attack never previously used in the target location and therefore went completely undetected before the event.
With the terrorist threat high on the agenda of many country's defence priorities, governments have realised the threat remains ever-present, and a large-scale CBRNe attack could be worse than any type previously witnessed.
To stay ahead, military and civil defences are working closely with researchers to ensure even the newest CBRNE threats are detected early and accurately.
The public may never know how many potential attacks have been prevented through detection and early intervention.
Cutting-edge technology combined with the vigilance and action of trained personnel strives to ensure this remains the case in any eventuality.