Attack Used ‘Very Small Amount’ of Liquid Poison, U.K. Says

A “very small amount” of liquid nerve agent was used in the March 4 poisoning of Sergei V. Skripal and his daughter, and it did not release gases or vapors, British environmental scientists said Tuesday.

The announcement came as the police prepared to withdraw from nine operational crime scenes in the medieval city of Salisbury and hand them over to scientists for a meticulous decontamination program.

Already, tourists visiting Stonehenge and Salisbury’s 13th-century cathedral have gawked at crime-scene tape surrounding a series of sites that the two Russians visited on the day they were found collapsed on a bench beside the Avon River.

A decontamination process could go on for “a number of months” and promises to be a vast undertaking, requiring backup from 190 army and air force specialists as well as input from the Defense Science and Technology Laboratory, the Home Office and the Ministry of Defense, the authorities said.

They warned that barriers would be erected at the affected sites, and that military troops, police and firefighters would be dressed in hazardous material suits. They would take a vast number of samples from the sites to test for traces of nerve agent, and incinerate or chemically clean contaminated objects.

The contaminated sites trace the Skripals’ path through Salisbury on the day of the crime.

The most contaminated is Skripal’s modest brick home, where there is believed to be “object zero,” the surface used to expose the victims. Once exposed, the father and daughter proceeded to a pub and a restaurant in a quaint downtown area. After exiting the restaurant, angling across a grassy area toward their car, the two became suddenly ill, vomiting and collapsing on a bench.

Shortly thereafter, they were loaded into ambulances, which were then potentially contaminated. A police officer who traced their path, Detective Sgt. Nick Bailey, was then exposed, and his house will also be decontaminated.

Matthew Dean, a Salisbury city councilor, said the announcement should reassure tourists, who typically feed the city’s economy during the warm months of summer.

“They say the sites will be clean, there won’t be any trace elements,” he said. “That’s an astonishing thing to say.”

He said he hoped that the spy scandal would not deter tourists, and that eventually it might become part of the city’s allure.

“It is so important that Americans come and support their British allies by spending dollars in this medieval city,” he said. “This thing is moving to history. People are going to talk about the spring of 2018.”