Novichok agents were used in the Salisbury attack – but how do they work?

On March 4 2018, Sergei Skripal and his daughter, Yulia, were found slipping in and out of consciousness on a Salisbury park bench. Authorities later revealed they had been poisoned with a nerve agent called A-234 Novichok. But how exactly does it work, and what does it do?

Novichok are a variety of nerve agents – chemicals which disrupt the pathways in which nerves transfer vital messages to organs in the body. They were developed in the Soviet Union and Russia between 1971 and 1993, with the scientists involved in the creation claiming they are the deadliest chemical of its kind ever made.

The group of chemicals was created to be virtually undetectable by NATO’s chemical detection equipment at the time, but to also be safer to physically handle.

They have wide series of devastating bodily effects, from nerve damage to heart failure.

The physical effects of Novichok agents on the human body. Photo: Abigail Devon Sawyer-Parker.

They produce these effects through one main mechanism: they stop a protein called acetylcholinesterase from working. This protein usually breaks down a neurotransmitter called acetylcholine. With this protein unable to work, acetylcholine builds up at neuromuscular joints and causes skeletal muscles to contract.

As the muscles are no longer functioning properly, the heart and diaphragm don’t work – this causes heart failure and fluid build-up in the lungs, and eventually, death.

Nerve agent uses like these are extremely rare, though, and an incredibly thorough clean-up operation is underway in Salisbury right now.