What is the latest development in the Salisbury nerve agent attack?
Former Russian agent Sergei Skripal is no longer in a critical condition and is responding to treatment, according to doctors at the Salisbury district hospital.
Skripal and his daughter, Yulia, were poisoned with a nerve agent called novichok in Salisbury on 4 March, and police officer Nick Bailey was also taken to hospital after being exposed to it. On Thursday Yulia Skripal issued her first statement since the attack saying that her strength is growing daily, but that the incident had been disorienting.
What does novichok do?
Like other nerve agents, novichok is an organo-phosphate. It affects an enzyme in the body, preventing the breakdown of a chemical called acetylcholine that among other functions helps to transmit signals between nerves and muscle.
That can suppress breathing and heart rate, causing coma and death.
Treatments for exposure to such nerve agents include atropine, which blocks the action of acetylcholine, while sedatives might be used to prevent seizures. But ultimately recovery depends on the body producing more of the necessary enzyme, which takes time.
Is it possible to get an idea of the dose of novichok from the Skripals’ conditions?
It’s unlikely. Dr Michelle Carlin, a senior lecturer in forensic and analytical chemistry at Northumbria University, points out that many factors might affect an individual’s condition.
“It will be down to what was given to them, how it was administered,” she said. “Both of [the Skripals] have different responses – you don’t know if that is because of their age or their own health status, or whether it is the way that it has been absorbed into the body or by how much they were exposed to originally.”
The speed at which medical help was given would also affect recovery, Carlin added. “There’s no way any toxicologist worth their salt would go back and tell you how much of a dose was taken based on symptoms,” she said.
Dr Chris Morris, of the medical toxicology centre at Newcastle University, also said it would be difficult to assess how much novichok Sergei Skripal was exposed to. “I think the best you could probably say is that it was a fatal dose that he had, and I think the issue here is that the responders – the emergency care teams, the paramedics etc – they got in so quickly that they’ve managed to support all three [victims – including DS Nick Bailey] to the highest level,” he said.
Will the Skripals make a full recovery?
Experts say it is impossible to know at present since there is little information about the long-term impact of novichok.
“The thing is with the novichok agents we don’t really know an awful lot about them, other than what has come from historical research,” said Carlin. “In those cases there has been some long-term neurological damage, but then you don’t know how much they were exposed to, how quickly they were treated versus the Skripals.”
If there is neurological damage, it could take several forms. “This may include things like slowing of thought processes, a reduction of physical movement and respiratory problems – but we don’t know yet whether those will happen in this case,” said Carlin.
But Morris said the signs were positive for the Skripals, adding that Bailey, the police officer, also appeared to have made a good recovery. “There is no reason to figure that Mr Skripal is not going to be the same,” he said.
Does novichok affect memory?
“Anybody who has been in a coma or sedated for that length of time is going to have poor memory surrounding the event,” said Morris. But he added that it is more likely that novichok will affect focus on events rather than memory itself.
What sort of care will the Skripals need now?
Morris said ongoing care would depend on how the individuals respond but that, as with any traumatic event, psychological support would be important, and physiotherapy might also be necessary.
Are the Skripals up to being questioned to shed more light on the attack?
That depends. “I am sure the police and authorities will want to question them, but it is going to be down to the clinicians and [the Skripals] themselves as to whether or not they feel as though they are able to do that,” said Morris.
