A year after the nerve agent attack on Salisbury, Jason Regent is still startled by the sound of sirens.

“Every time I hear an ambulance I think: ‘Is it happening again?’” says Regent, who runs a tailoring shop in the city. “I’m a little bit scarred. It was like being in a film with all the helicopters clattering overhead.

“We used to struggle to explain where Salisbury was to people. We would say we were near Stonehenge. Now the whole world knows us.”

Regent was cycling with his nine-year-old son in Salisbury when the former Russian spy Sergei Skripal and his daughter, Yulia, collapsed on a park bench on Sunday 4 March.

As it became clear over the following weeks that Skripal had been the victim of an assassination attempt, it deeply affected both Regent and his son. At one point the boy had to go to A&E after suffering a panic attack. “He is still reluctant to sit on park benches,” said Regent. “It makes him anxious.”

At the Casa Fina gifts and accessories shop on High Street, owner Susi Mason said it was hard to believe that two would-be killers armed with the nerve agent novichok were sent at the behest of the Russian state to Salisbury. “You could never have dreamt of something so bizarre happening in a quiet corner of England. I think people were affronted.”

Susi Mason at her shop Casa Fina in Salisbury. Photograph: Sam Frost/The Guardian

Like most of the shops in Salisbury, the attack affected Mason’s business. Footfall in the city remains around 10% down. “I suppose if you are going to visit a cathedral city and you’re thinking of York, Winchester, Truro or Salisbury, maybe this wasn’t the year when you’d have chosen Salisbury,” said Mason.

Anne Sykes, who lives in the city centre, said she was never fearful. “I grew up in London in the 1970s when the IRA were setting off bombs,” she said. Sykes was shocked when a London friend wondered – only half-jokingly – if it was safe to shake her hand. “I told them: ‘You have more chance of catching something strap-hanging in the tube than you have of getting novichok from me.’”

That sort of attitude lingers. A school sports team from another part of Wiltshire arrived in Salisbury last week and jokingly warned each other not to drink the water or not take in too much air. Such teasing still grates in the city.

On Sunday the city was reflecting on the events of a year ago and looking forward. Robed dignitaries celebrated the anniversary of the granting of Salisbury’s charter with a procession to St Thomas’s church.

“It’s a chance to remember what happened and how difficult it has been but also to celebrate what we’ve learned about ourselves,” said the rector, the Rev Kelvin Inglis. “I think Salisbury has understood better the values we share as a community and a city. In the face of the evil and indiscriminate attack, we uphold the rule of law, the freedom to live in peace, and care and concern for the vulnerable in our midst.”

Rev Kelvin Inglis, rector of St Thomas’s church. Photograph: Sam Frost/The Guardian

Many heroes have emerged over the last 12 months – the armed services personnel in the hazmat suits who put their lives at risk; the police and other public servants who worked excruciatingly long hours; the postal workers who had to cross the cordons to deliver to Skripal’s former neighbours; those who helped the homeless people when they were forced out of their car park encampment next to the bench where the former spy collapsed.

The government has handed back the Skripal house – where he is believed to have been poisoned – to the council after months of decontamination work, effectively declaring the county free of novichok. But are the authorities sure Wiltshire is now safe?

Dawn Sturgess, who died after being exposed to the nerve agent novichok. Photograph: Metropolitan Police/PA

The death of Dawn Sturgess in July still gives people pause. Sturgess fell fatally ill in Amesbury, 11 miles north of Salisbury, after her partner, Charlie Rowley, gave her a perfume bottle that turned out to contain novichok.

The thesis the counter-terrorism police appear to be working on is that the bottle used by the attackers to spray novichok on the door handle of the Skripal house was then discarded by them and found by Rowley. But Rowley claimed that the perfume bottle he found was boxed and sealed – which could suggest that this was a second container, and leaves the possibility of there being others.

Wiltshire deputy chief constable, Paul Mills, pointed out that nobody else has fallen ill since July. But the disconcerting message from Public Health England remains that people should not pick up anything if they didn’t drop it. “We’re confident that is the right message,” said Mills.

Alistair Cunningham, the chairman of the South Wiltshire recovery coordination group, said the one-year mark was an important milestone. “We will revisit all the businesses and all the people one year on just to check how they’re faring and then we’ll do that periodically as we move forward,” he said. “It is an ongoing thing.”

More people are seeking help for the psychological impact. “These things play out for a long time in people’s minds,” said Cunningham. “You see more cases of people coming forward thinking: ‘I don’t feel right.’”

Salisbury cathedral, one year on from the novichok attack in the city. Photograph: Finnbarr Webster/Getty Images

Amesbury can get a little forgotten but the impact is felt keenly there. One of Rowley’s neighbours, Rosemary Northing, said there was great sorrow for Sturgess in the area and she felt the place was “tainted” by its accidental association with the attack.

Tiny things have slipped. Northing, for example, wanted to begin a rock-hunting group, in which participants hunt brightly painted pebbles that have been secreted away. “I meant it to be a way of bringing the community together. Obviously we haven’t been able to do that,” she said. Many complain that the place is a little scruffier because the advice on not picking anything up means that collecting litter remains off limits.

There is much to look forward to this year in Wiltshire. The county will host Armed Forces’ Day in June – exactly a year after Sturgess fell ill; a major cycle race is expected to pass through; an ambitious arts festival is taking place.

The cathedral is already planning the celebrations of its 800th year in 2020. Its visitors are down 15% year on year but the Dean, the Very Rev Nick Papadopulos, said a corner had been turned.

“We are blessed to live and work in one of the most beautiful cities in England,” he said. “We are built where five rivers meet; we are surrounded by water meadows; our medieval street pattern is still evident. It’s no wonder [painter] John Constable loved it here. And we have a proud history of creative artistic endeavour.

“I believe that in the wake of 2018 we treasure that more than ever and are determined – together – that it should flourish. There is a lot of work to do to make up the ground that was lost last year – but I sense a confidence in the city that we can and will do this.”