Smash hit

“We shouldn’t be complacent, but it is important for the public to realise that while there would be deaths, as there would be in conventional attack using explosives, there would not be the kind of widespread catastrophe that they might imagine.”

MacDonald adds: “In the event of a biological release, we’d begin to see a picture emerge in the same way as we would monitor, say, a flu outbreak. We have systems in place for GPs to report people displaying certain symptoms and we get feedback from the NHS Direct helpline. The Department of Health’s Emergency Operations Centre in London would then co-ordinate a response based on the analysis of pathogens at the labs here.

“We then initiate a programme of tracing people with whom victims have come into contact and what we call ‘ring vaccination’. People most closely exposed are treated with the relevant medicines, while we give prophylactic ive vaccines to stop the disease spreading. That is how smallpox was eradicated in the 1970s. We are not saying that there might not be fatalities, but we could prevent any widespread disaster.”

So what about the deliberate release of a chemical or nerve agent? “The most likely release would have to be in an enclosed space, such as the Tube system, because these agents disperse and become harmless very quickly in open spaces,” says Lightfoot. “The first people on the scene would be the emergency services, particularly the fire service. They have protective clothing and equipment to establish whether the release is chemical or radiological.”

Immediately, a Multi-Agency Incident Assessment Team (MAIAT) would be sent in. These operate from specially equipped vehicles that circulate permanently, ready to attend any emergency. It is known that the MAIAT vehicles operate in London, but the HPA will not say whether they are operating outside the capital.

“Once an assessment is made, victims would be taken away from the incident as soon as possible. In the event of a nerve-agent attack they would be given atropine, an antidote that can save lives if administered quickly,” says Lightfoot.

“All ambulance services have nerve-agent antidotes. Again, let us not pretend that there would not be fatalities, but they could be limited by swift action. Twelve people died in the Tokyo incident, which was a tragedy, but you might argue that more would have died in a conventional explosion. So the main effect here would be psychological, and would not necessarily result in more deaths than a conventional attack.”

But what about a dirty bomb? Surely that would be catastrophic? Again, not necessarily. The MAIAT teams or fire services, which have radiation detectors, and police would quickly remove people from the scene and put them in mobile decontamination units — mobile showers, in effect — to remove radioactive particles.

“Those closest to the release would be worst affected, but the most serious damage would be caused by the actual explosion,” says Dr Michael Clark, of the HPA’s Radiation Protection Division. “By its very nature, as the radioactive substance was dispersed, it would become less dangerous to human health. There might be areas that would have to be evacuated for a time and decontaminated, but the worst-affected area would be relatively small.”

According to Clark, the actual construction of a dirty bomb mitigates against its effectiveness. The most likely radioactive source would have to be built up over time by gathering industrial or medical radioactive substances rather than by using a source used in making a nuclear weapon. Such fissile material is not necessarily highly radioactive in itself. “They’d try to get hold of caesium-137, cobalt-60, strontium-90 or irridium-192 in small amounts over time,” he says. “But being exposed to that would make them very sick very quickly. Within days they wouldn’t be able to function and would die. Even with people prepared to commit suicide, that would require a large team to steal the sources, make the bomb and deliver it. They could survive longer with small amounts but that would make a dirty bomb less effective.”

But isn’t this simply a group of government boffins trying to make us feel a little less frightened? Not necessarily. Independent experts I spoke to generally agreed with the HPA’s assessments. Professor Christopher Bellamy, the director of the Security Studies Institute at Cranfield University, says: “Historically, the use of chemical or biological weapons has been regarded as unreliable and indiscriminate by armed forces. That might not deter terrorists because their aim is not efficient killing.

“Similarly with radiological weapons. If you evenly distributed 1kg of a highly radioactive substance across London — which is quite an amount — the readings would be above EU safety levels, but they would be unlikely to do any serious harm.

“The terrorists might achieve their aim — to terrify people — but the casualties would probably not be high.”

Michael Clarke, Professor of Defence Studies at King’s College London, agrees. “Photogenically, there is nothing like an explosion for terrorists to get their message across. In terms of killing people, that is still the most effective. Any chemical, biological or radiological attack would appear so sinister that it would raise fear levels in any population, but the actual effects need not be disastrous.”

It is only natural, then, that we should be afraid of such attacks and prepare for them, but their main aim would be to cause maximum panic rather than maximum casualties.

Much has been made recently of the brave response of Londoners to the bombings on 7/7 and their determination not to be intimidated by terrorists. “We Are Not Afraid” has become a catchphrase. So a chemical, biological or radiological attack might not kill or maim any more of us than a simple, terrible bombing. But it would surely be a time to find out just how stiff that upper lip really is.