Paramedics saved the life of one of the Wiltshire novichok victims by administering an anti-nerve agent drug at the scene that had never been used on a patient before in the UK, it can be revealed.

The Guardian has also learned that a number of paramedics have reported feeling ill after being present at the Salisbury and Amesbury incidents.

One of the paramedics who had helped the former Russian spy Sergei Skripal and his daughter when they collapsed in Salisbury was among those who went to the aid of Charlie Rowley when he also fell critically ill four months later in Amesbury.

‘The whole world knows us’: Salisbury one year on from novichok attack Read more

Instinct told him that a second nerve agent poisoning may have taken place and Rowley was given the drug. Speaking in detail for the first time about its role responding to the poisonings a year ago, South Western Ambulance Service NHS foundation trust (SWASFT) said it believed this saved Rowley’s life.

SWASFT also confirmed that staff had reported symptoms including headaches, sore throats and eye problems, and that some remained concerned about the possible long-term effects on their health. The health problems reported by the paramedics raise the possibility that more people were affected by novichok than has been officially stated.

The attack on Skripal and his daughter, Yulia, in March last year was the first time chemical weapons had been used in Europe since the second world war and put huge pressure on all the emergency services.

Wayne Darch, the head of emergency preparedness, resilience and response at SWASFT, said: “There wasn’t a plan on the shelf for what we were dealing with. We were writing the book as we were dealing with the situation put in front of us. It was intense.” SWASFT believes the actions of its staff tending to the Skripals at the scene and in ambulances on the way to Salisbury district hospital also saved them.

Almost four months later, on 30 June 2018, Rowley and his partner, Dawn Sturgess, fell ill at his flat in Amesbury, eight miles north of Salisbury, after opening a fake bottle of perfume that he had found in a charity shop bin. It turned out to contain novichok.

Sturgess sprayed it over her wrists and became severely ill. Paramedics were called to help her on the morning of 30 June and she was taken to Salisbury district hospital.

When they were called again to the same flat later that day to tend to Rowley, a lead paramedic who had been present when the Skripals fell ill suspected that nerve agent was again involved. Rowley was given an anti-nerve agent drug that British crews began to carry at the height of the al-Qaida threat but had not used until then.

Rowley survived, though he continues to suffer physically and mentally. Sturgess, a mother of three, died.

Darch said the first call to Rowley’s flat following Sturgess’s collapse came at 10.15am and the response was relatively straightforward. There was nothing that made the paramedics think that it could have been a second novichok poisoning.

When a second 999 call came through at 6.20pm for the same address, the control room flagged this up to the local commander. “It’s unusual that we would get called to the same address on the same day for two separate patients,” said Darch. By chance, the commander was one of those that had helped the Skripals. He attended Rowley’s address in person.

“The crew that attended Charlie took a particular course of treatment,” said Darch. “When that wasn’t effective, they suspected that it may be nerve agent.”

Though there was no information or intelligence that Rowley had been the victim of a nerve agent, the paramedics donned protective clothing – Tyvek suits, face masks, gloves and aprons – and treated Rowley as if there had been a second attack. Darch said: “They did a fantastic job under difficult circumstances and undoubtedly saved Charlie’s life.”

After the two sets of poisonings, SWASFT leaders coordinated a huge mapping exercise to pinpoint people, buildings and vehicles that could have been contaminated. Eight of the 10 vehicles used in the two incidents by 18 staff members have been destroyed and two ambulance stations were temporarily closed. Wiltshire air ambulance was twice grounded.

But the most worrying element for some staff and their families is the idea that their long-term health may be compromised by exposure to novichok.

Some staff have reported symptoms including headaches, sore throats, tiredness and conjunctivitis. The trust confirmed that a few had gone to the emergency department at Salisbury for advice.

Darch said: “No ambulance staff became acutely unwell, which is testament to their professionalism and the way they treated those patients.” Asked to define acute, Darch said: “We don’t know, I don’t know what the low-level impacts of novichok would be. Are the headaches associated with it? I don’t know.”

Staff underwent blood tests and were judged all clear for novichok, the trust has said. Asked if he was confident the tests have shown nobody was affected by nerve agent in any way, Darch replied: “At an acute level, yes, absolutely.”

Asked if he was concerned about possible long-term effects on paramedics, Darch said: “Everything that we have put into place continues to be available for staff. We recognise there are still concerns and are doing what we can to support individuals. We will continue to do so.”

The trust said a range of measures were put in place for staff. It added: “We recognise that this was a difficult and uncertain time for our crews. They received daily contact from their managers, one-to-one sessions, group debriefs, specialist TRiM [trauma risk management] and counselling sessions, health monitoring from Public Health England and rapid access to occupational health and the trust’s staying well service. This was also made available to their families.

“They all also received specialist advice and support in line with Public Health England guidelines in relation to a range of concerns, including signs, symptoms and blood testing as well as quarantine for equipment and uniforms. Access to this support continues to be available to any member of staff who has any ongoing concerns.”

Rowley had not been aware that he was treated for nerve agent in Amesbury. When the Guardian told him what SWASFT has revealed, he said: “I don’t remember it at all but I’m very grateful for the way they treated Dawn and me. I have to take my hat off to everyone who helped us.”

Sturgess’s mother, Caroline, said emergency services sometimes got forgotten. “I can’t thank them enough for doing everything they could to save Dawn,” she said. “I know in my heart of hearts that everyone did everything in their power to save her and that’s a comfort for me. They were very brave.”