Formula 1 has played down suggestions next weekend’s Canadian GP might have to be cancelled.
On Wednesday, we reported that local forest fires had blown a blanket of smoke over the greater Montreal area - where F1 will gather at the Circuit Gilles Villeneuve.
"Those with respiratory issues, such as children with asthma, are advised to avoid strong physical activities outdoors until the warning is lifted," the report said.
The sheer amount of smoke was so extreme as it drifted south that tens of millions of US residents were also issued alerts about the quality of the air.
However, by Thursday, Environment Canada had lifted the smog warning for Montreal, adding that the air quality should return to "low risk" by Friday.
"The event is not at risk," a spokesman for Formula 1 was quoted as saying by various international sources.
"We have been assured that the situation in Montreal is different to other parts of the country and northern US.
"Risks remain low and Montreal’s air quality is assessed as good," he added. "At no time was there any requirement for residents to stay indoors or restrict their movements outdoors.
"These fires are 800km from the circuit and do not pose any risk on their own, but the winds have carried the smoke to other parts of the region."