U.K. authorities have confirmed two British citizens are critically ill after being exposed to the Novichok nerve agent, the same chemical that nearly killed former Russian agent Sergei Skripal and his daughter, Yulia, nearly four months ago.
A 44-year-old woman and a 45-year-old man were hospitalized after an apparent chance encounter with the nerve agent near the site of the March attack on the Skripals.
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Here’s what we know so far.
What is Novichok?
Novichok is actually a group of poisons first developed by the Soviet Union in the 1970s and 80s. There are several variants of Novichok, a binary weapon containing two less toxic chemicals that when mixed react to produce a poison several times more lethal than sarin or VX.
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What do nerve agents do to the body?
According to University of Leeds’ professor Alastair Hay, nerve agents block a specific enzyme that “regulates messages down nerves and at junctions between nerves and muscle.”
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“So nerve agent poisoning prevents and interferes with lots of essential body processes,” the environmental toxicology professor said. “The consequences of being exposed to a nerve agent include the risk of heart attack and damage to the brain through poor oxygenation, so it is essential to prevent that from happening in these two patients.
“It is possible that the pair will be being kept sedated for some time to prevent overactivity of nerves in the brain, to prevent seizures and other damage,” Hay said via London’s Science Media Centre.
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Nerve agents can linger
The Skripals were found unconscious on a bench outside The Maltings shopping centre in Salisbury on March 4. It was later revealed that Novichok was used in form of a gel and was smeared on the door handle to the ex-spy’s house.
READ MORE: Unknown substance leaves 2 people critically ill near Salisbury: British police
“Confirmation that this was the same chemical agent that poisoned the Skripals really confirms a lot of things that we believed were true about this Novichok class of nerve agents,” Andrea Sella, professor of inorganic chemistry at University College London. “They are designed to be quite persistent – they hang around in the environment, neither evaporating nor decomposing quickly.”
The pair were found unconscious at an address about 11 kilometres from where the Skripals were found poisoned.
“That means that if a container or a surface was contaminated with this material it would remain a danger for a long time and it will be vital to trace the movements of this couple to identify where they might have come into contact with the source,” Sella said.
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Health officials said the risk to the public remains low, but they advised the public to regularly wash their hands and clothing.
“The chief medical officer’s advice to those concerned to wash clothes and wipe down personal items with baby wipes, and that people don’t need to seek medical advice unless they are experiencing symptoms, is, as she said herself, prudent and practical,” Hay said. “It would be sensible to follow this guidance.”
–with files from the Associated Press