A smog advisory is in effect for Ottawa and the surrounding area as winds continue to blow smoke from dozens of forest fires in Quebec into eastern Ontario.

Ontario's Environment Ministry issued the smog advisory late Monday morning, noting that polluted air from the fires is blowing east, resulting in high smog levels in eastern Ontario.

Residents in the Ottawa area woke up Monday to a hazy skyline, and an overpowering smell of smoke hanging in the air.

Fire officials say forest fires in the Trois Rivieres area are causing the smoky haze. More than 50 forest fires are currently burning in Quebec; most of them north of Montreal.

The smog advisory in Ontario covers: Ottawa, Brockville, Leeds and Grenville, Cornwall, Morrisburg, Prescott and Russell, Renfrew, Pembroke, Barry's Bay, Smiths Falls, Lanark and Sharbot Lake.

The Environment Ministry says the smog advisory will stay in effect until further notice.

No fires in Ottawa

Emergency services in Ottawa received more than 180 calls on Monday from residents concerned about the smoke. Firefighters responded to 40 of those calls, examining the greater Ottawa area for any signs of fire. However, no fires were reported.

"For a short period of time it was chaotic. A lot of our vehicles were tied up, but not on priority," said Marc Messier, spokesperson for Ottawa Fire Services.

"We're still getting the odd call, still sending the odd truck out. (We don't want to) take any chances and we're making sure there's nothing serious."

Smog risk

Ottawa's top medical officer of health says those most at risk on smoggy days are residents who have asthma and lung problems. Those with heart disease are also at risk.

"We know smog certainly makes breathing difficult for people, especially people with chronic respiratory illnesses - asthma, chronic obstructive airway disease, emphysema. These are people who will struggle when the air quality is bad," said Dr. Isra Levy.

Doctors say smog can act as a deterrent, narrowing the airways and making it difficult for people to breathe.

"The worry is that if people with chronic cardiovascular or lung disease go outside and exert themselves, they might have adverse events," said Dr. Shawn Aaron, a respirologist at the Ottawa Hospital.

"They might get short of breath, have an asthma attack or breathing attack, and on days like this we see emergency visits go higher because of things like this."

Stay indoors

As a result, residents who have difficulty breathing are advised to stay indoors and limit physical activity.

For 18-year-old Kelsey Lett, the heavy smog meant staying home from school.

"It makes me want to cough, get short of breath, it's hard to breathe, which means I can't go outside," said Lett, who has cystic fibrosis.

"It happens like that. I walked outside, it doesn't take long for it to get to my lungs."

Although health officials warn smog can also reduce lung function in otherwise healthy people, Levy said healthy residents don't need to limit their daily activities because of the smog.

"We know that smog is a dangerous thing. We know that especially for people that have underlying risk factors that over time smog will cause problems.

"But in terms of your physical activity today and your daily activities, it's not something that you need to limit if you're otherwise well and you're not having any symptoms, then carry on with your business as usual," Levy said.

However, those who have angina or other heart conditions may continue to experience problems two or three days after the smog lifts.

With a report from CTV Ottawa's Joanne Schnurr