Novichok 'hotspots' still a threat to public
Confirmation that two more people in Salisbury have been poisoned by Novichok has raised questions over whether the multi-million pound decontamination effort failed.
After it was used in the attack on Sergei Skripal and his daughter Yulia on March 4, Salisbury had been declared safe.
But four months later a trace of the substance has poisoned Charles Rowley (45) and his girlfriend, Dawn Sturgess (44).
Nine "hotspots" from the original attack, where residual traces could have remained, had been identified and were being decontaminated.
It was unclear whether the new poisonings were the result of a previously unknown "hotspot" or if a small amount of the agent somehow escaped the clean-up, perhaps on someone's shoes.
Hamish de Bretton-Gordon, the former commanding officer of the UK Chemical, Biological, Radiological and Nuclear Regiment, said the nerve agent is probably only dangerous if ingested. It was likely the pair touched a molecule or two of the Novichok, and then may have put their fingers in their mouths.
The chemical weapons expert told the Radio 4 'Today' programme: "I think it's clear that they were contaminated or contaminated themselves rather than being attacked.
"It's also quite clear that they had a rather large dose. We know from the 32 people who presented themselves after the Skripal attack that some of them had 'brushed past' some Novichok and didn't become ill. I think it is the ingestion of this Novichok that has made them seriously ill."
He explained: "If you ingest this stuff, that's how the nerve agent works; if you brush past it, your skin is actually very good at preventing absorption, so I think that's the key here. Maybe some debris or collateral from the original attack has been handled by these people.
"I think the message to everyone in Salisbury [is] there's very little danger. But people should be vigilant there's no sort of picking up any sort of medical paraphernalia or syringes.
"There is very little threat left from the Novichok - unless it is ingested. There may be a couple of molecules left in the Salisbury area from the original attack. These are the first casualties we've seen since March so we can see how rare this stuff is - and if you don't ingest it, you're probably not going to become ill."
Following the Skripal poisoning, some scientists had suggested Novichok, as an organophosphorus compound, would degrade quickly with water like other nerve agents, and areas associated with the attack were hosed down.
However, it emerged it is a nerve agent of high purity and persistence. It is not affected by weather conditions, and may not have degraded as quickly in the environment as other similar substances.
It also had what experts called an "additional toxicity", meaning even having degraded it could still pose a danger after a period of time when other agents would not. At a public meeting six weeks after the Skripal attack, Ian Boyd, chief scientific adviser to Defra, the UK food and environment ministry, issued a prophetic warning.
He said: "You are underplaying the toxicity of this chemical. You're also underplaying how the chemical has been spread. It does not degrade as fast as you think it does. You can assume that it is not much different now from the day it was distributed.
"We have to make the assumption that in certain circumstances there will be relatively high concentrations, probably at very specific locations, which could be at levels that are toxic to individuals.
"We do know there are hotspots like that. We have to make the assumption that there are still hotspots to find."
His remarks led to an official response from Defra and Public Health England that "Salisbury is safe for residents and visitors" and "there is no need to take any additional precautions."
It said "appropriate measures" had been taken at each hotspot where the Skripals had been, to ensure there was no additional risk to the public. But several of those hotspots were not cordoned off immediately. Neil Basu, assistant commissioner of specialist operations at Scotland Yard, said the priority was to establish how they have come into contact with the nerve agent.
A number of sites in Amesbury and Salisbury, where the pair visited before they fell ill, have been cordoned off. And in a move to reassure the public, he said there was "no evidence" that either of the pair recently visited any of the sites decontaminated following the Skripal attack. (© Daily Telegraph, London)