At the end of last month, I closed a meeting in Defra in London in which we agreed to advise ministers that the final site identified in Salisbury as needing specialist clean-up was safe. This was the final chapter in the follow up to the novichok nerve agent attack on 4 March 2018. For almost a year many dedicated people had laboured to reach this objective and we were closing down one of the most shocking incidents in recent British history.
I am the Chief Scientific Adviser at Defra and it was my job to constitute and oversee the process which would provide assurance that sites were safe to be released back into public use following extensive testing.
On 4 March 2018 Yulia and Sergei Skripal were poisoned by novichok, a liquid nerve agent.
It threatened their lives, and those of other citizens in Salisbury, including Detective Sergeant Nick Bailey. On Saturday 30 June 2018 two people were admitted to Salisbury District Hospital having been taken unwell in a private property in Amesbury. Dawn Sturgess tragically died on the evening of Sunday 8 July, while Charlie Rowley survived thanks to heroic efforts of the first responders and emergency services. Both were further victims of the novichok nerve agent.
I want to tell the story of how we have cleaned up the 12 sites identified across Salisbury and Amesbury as needing some level of specialist decontamination. Public Health England advice is that the risk to the public remains low, with no further cases of illness linked to this incident.
Many people will have heard of COBR, the top emergency response function within government. Alongside COBR is an advisory committee called SAGE (Science Advisory Group for Emergencies) which can be stood up in a matter of minutes to hours depending on the need. This COBR-SAGE structure swung in to action within minutes of confirmation that a nerve agent had been used in Salisbury.
Government is not caught off guard when these things happen. We regularly exercise this system of response because sadly we know this is a threat which exists.
Novichok itself is highly dangerous and difficult to detect. SAGE considered the evidence about novichok to inform it about what the effects were likely to be. This knowledge was critical to our clean-up operation.
Events like the Salisbury poisoning have two phases; the first is the response phase, led by the relevant government department. In this case the Home Office coordinated the immediate response, after which it fell to Defra to marshal the recovery, including the clean-up.
We brought together all the expertise which can be brought to bear on this difficult problem including military and civilian capabilities. This exists to protect public health and is always ready to swing in to action. It was last used operationally in 2006 when Alexander Litvinenko was poisoned with polonium-210, a radioactive material.
The activity was supervised by a body known as the Decontamination Science Assurance Group (DSAG) which I chaired, bringing together experts in chemistry, statistics, toxicology and public health. DSAG’s role was to assure ministers that each contaminated site was clean and could be released back to public use.
The use of a nerve agent in a British city is unprecedented and required a process to be established from the outset to make sure each site could be declared safe. Our priority was to get South Wiltshire back to normal as quickly as possible, but we would not compromise on safety and took a highly precautionary approach to our decontamination process. This involved testing for the presence of novichok, cleaning and re-testing for presence. This was repeated until we saw no more novichok. The procedure was technically challenging and rigorous, often involving experimenting with different cleaning methods and understanding how the chemical interacted with different surfaces and how it moved around.
To create even more rigour I asked an independent observer from outside government and outside the immediate circle of experts to audit and challenge our decisions and also to observe how we worked.
Dstl had the technical ability to detect extremely small quantities of novichok using methods which were independently verified by the Organisation for the Prevention of Chemical Weapons (OPCW). Our ability to detect novichok got progressively better and this allowed us to develop a detailed picture of the patterns of contamination.
While we obviously wanted to minimise disruption, the thoroughness of our procedures led to some of the most contaminated locations being substantially deconstructed. This was necessary to comply with our exacting standards of cleanliness.
In total we decontaminated 12 sites across Salisbury and Amesbury. The process also included the decontamination of personal property and vehicles. The methods we used placed the protection of public health as the absolute priority.
It says a lot for the efficiency of the standard barrier and cleaning methods used to protect first responders from the NHS who attended the casualties and treated them later in hospital that none of them suffered any ill-effects from the agent.
I was often tempted to join those doing the work on the ground to carry out the testing but, in practice, this would have been a bad idea. DSAG needed to maintain a distant and objective relationship with those undertaking cleaning. DSAG’s priority was to safeguard the standards.
At the centre of this, was our military-led taskforce, carrying out the cleaning and sampling with the utmost professionalism. Mostly clad in extremely uncomfortable suits which gave them the protection they needed to work with this highly toxic substance, these heroes worked through the heat of the summer of 2018 cleaning and sampling, cleaning and sampling. Both the response and recovery operations were supported by the significant expertise of Dstl, including the laboratory technicians who have analysed literally many thousands of samples in high containment laboratories, again clad in protective gear.
There are many unseen heroes in this story. From the first responders who had the insight to understand what they were beginning to see, to the nurses and doctors who worked tirelessly to save lives and the military and civilian experts who did the chemical analysis and cleaning. It is hard to overstate my admiration for these people who swung in to action as a team. If those who carried out the despicable act of deploying a nerve agent in the middle of an iconic and beautiful English city thought they could break the spirit of those who would respond then they were seriously mistaken.
We have learned a lot as a result of this experience. It should never have happened but the good message is that we will be even better prepared if there is a next time, and we will share our knowledge through the OPCW in ways which help others also to resist this kind of belligerent attack.