The streets of Bordeaux on Sunday bore an unsettling resemblance to the darkest days of the Covid-19 pandemic with many residents once again wearing surgical masks, FFP2 respirators and homemade cover-ups.

This time, however, they were not trying to protect themselves from a virus but from the toxic smoke billowing from a massive wildfire that has been raging across the southwest Gironde region.

Read moreBordeaux under threat as France and Spain battle ‘unprecedented’ wildfires

Since Friday evening, Bordeaux has been covered by a thick plume of smoke containing fine particulate matter. Ash has settled across the city while the smell of burning lingers in the air.

‘It changes constantly with the wind’

The yellow-tinged haze has done little to empty the bustling Rue Sainte-Catherine, one of Bordeaux’s main shopping streets.

Among those out enjoying the summer afternoon were Laure and Claire. While Laure was dressed for the warm weather, Claire had added an FFP2 mask to her summer outfit.

Yesterday, when I went out to do some shopping, the air was completely unbreathable.

“Ash was falling on us,” Claire said. “I spent the night coughing. So this morning I went to buy this mask to try to protect myself as much as possible.”

Her friend had yet to make a trip to the pharmacy but shared the same concerns.

“What’s really difficult is that it changes constantly with the wind,” Laure said.

She has found her own way of monitoring the smoke.

“I have a little dog. He’s like a smoke detector and starts barking whenever the sky fills with smoke, as if he’s trying to warn me,” she laughed.

Her rule is simple: if her four-legged companion starts barking too much, it is best to stay indoors.

‘We only went out to fill up the car’

Mathilde and Jeanne also took their precautions.

Sunday was the first time they had left home since smoke descended on Bordeaux two days earlier.

“Yesterday we only went out to fill up the car, just in case we decided to leave the city,” they said. “But today we were starting to go stir-crazy, so we decided to take a short walk. We won’t stay out for very long.”

If air quality continues to deteriorate, the two friends say they may leave the city and return to their families in Nantes and the Paris region.

“We know breathing these fine particles is really bad for your health,” they said. “If it gets worse or lasts several more days, it’s better to leave.”

Smoke from wildfires releases gases and particles that can be harmful to human health, according to France‘s national health and food safety agency, Anses. These include fine particles that penetrate deep into the lungs, carbon monoxide, carbon dioxide and volatile compounds such as acrolein and benzene.

People living close to a wildfire may develop respiratory irritation, but the effects extend well beyond the immediate area, pulmonologist Bruno Crestani told AFP. Anyone downwind of a fire can be exposed to smoke “for several hours or several days”, depending on weather conditions, he said.

Anses advises people to limit travel and time spent outdoors, keep doors and windows closed, ventilate homes only when conditions allow and avoid outdoor exercise.

Authorities have distributed 1.5 million FFP2 masks for vulnerable people, with another 1 million on the way. Collection points are due to open at Bordeaux University Hospital for healthcare workers, while masks will also be available through pharmacies and the usual distribution network.

Read moreLive: Macron to visit fire-ravaged southwest France as new heatwave due in Europe

‘Choosing between ash and heat’

For Mickaelle, following the recommendations is easier said than done.

“I live right in the centre of Bordeaux, under a roof. It’s already 34C inside my apartment, but I can’t open the windows because all the smoke comes in,” she said while sitting at an outdoor café with her son and a friend.

“And there’s another heatwave forecast. Are we really going to have to choose between ash and heat?”

Along the banks of the Garonne River, Damien was equally resigned.

The police officer spent several days helping evacuate communities threatened by the wildfire and refused to give up the one activity that helps him unwind: exercising outdoors.

“Sure, it’s harder to breathe,” he said. “Anyway, I planned a shorter workout because I’m exhausted.”

Nearby, two children played in a park under the watchful eye of their mother and grandparents.

“We’re among the people who had to evacuate,” their grandmother, Gisèle, said from behind her mask.

The family fled the coastal town of Andernos on Friday evening and found temporary accommodation through friends in a suburb of Bordeaux.

Despite what Gisèle described as a “heavy” atmosphere, they ventured outside mainly to “keep the children occupied”.

“There’s now way we’ll ever go too far from home,” she said. “We left behind three cats. I want to be able to go back as soon as we’re allowed or even make a quick trip to collect them. I’m terrified they’ll run out of food and water.”

For now, the family fears they could be forced to evacuate again. Their hosts live in Blanquefort, close to neighbourhoods that have already been evacuated. Their suitcases are already packed.

Evacuation fears

The wildfire was about 15km from the Bordeaux metropolitan area on Sunday morning, according to local authorities.

Driven by erratic and shifting winds, the blaze has raised questions over how far it could spread – and whether it might eventually threaten the city and its 270.000 inhabitants.

Speaking from Bordeaux’s exhibition centre, where about 2,500 evacuees have been sheltering since Friday, Mayor Thomas Cazenave sought to dispel what he described as “false information”.

“I’ve read in the press, particularly the foreign press, that we have prepared an evacuation,” Cazenave said. “Let’s be perfectly clear: that is absolutely not on the agenda. The fire is further south, on the edge of the metropolitan area, but it is not advancing on the western flank. There is no point alarming people.”

The mayor stressed that the city remained on alert and was “preparing for every scenario”.

He said emergency accommodation was far from full and that the exhibition centre alone could house up to 10,000 people if necessary.

Even so, smoke and uncertainty have prompted some people to leave.

At Bordeaux’s main train station, many tourists chose to cut short their stays.

Luc and Ema, who had arrived the previous Monday for what was meant to be a 10-day visit, decided to head home early.

“We came to see friends and family, but given the situation we preferred to leave, especially with the air quality,” they said.

“We had mainly come to visit my grandfather, but because he’s elderly and has asthma, he has already left the region.”

Like many passengers, they also had to deal with cancelled trains and lengthy delays.

Rail services south of Bordeaux, in the direction of the wildfire, remain suspended. Meanwhile, trains heading north towards Paris are heavily booked as demand continues to surge.

This article has been translated from the original in French by Anaëlle Jonah.