How Bad Air Quality Can Impact Your Health

PHOTO BY OLLIE GRATZINGER | WILDFIRE SMOKE CAUSED A SMELLY HAZE OVER THE CITY ON JULY 18

These last few days, it has been unmistakable: that smelly, lingering haze blanketing the city, blurring the skyline and putting a damper on weekend plans with Air Quality Indexes surpassing 300. 

The smoke was from wildfires burning hundreds of miles away in Ontario and Minnesota, and while the worst of it has cleared, there’s no guarantee that it won’t return. 

Officials say the majority of Canadian wildfires burn in areas so remote and dense that access by road is nearly impossible, making them difficult to put out. Likewise, climate change is broadening the window for outbreaks of the dangerous smoke, as fire seasons in the west have become longer and more extreme.

As wildfires continue to burn, contaminated smoke can travel hundreds or even thousands of miles, impacting communities far beyond the areas directly affected by the fires — including Pittsburgh. 

“When smoke is combined with extreme hot weather, risk factors for heart attack and stroke, including high blood pressure, inflammation and clotting become activated, all of which can result in an acute cardiac event,” says Dr. Indu Poornima, a volunteer regional board member of the American Heart Association, professor of medicine and the division director of Clinical Cardiology & Imaging at the Cardiovascular Institute at Allegheny Health Network.

She adds that health risks extend beyond the breathing problems we typically associate with poor air quality.

“Wildfire smoke contains a number of pollutants, including fine, microscopic particles that have been linked to increased cardiovascular risk. While respiratory health impacts are often top of mind, these particles can also affect heart health,” she says.

According to AirNow.gov, a partnership between the U.S. Environmental Protection Agency and various other state, local and tribal air quality agencies, the Air Quality Index (AQI) is divided into six categories that correspond to different levels of health concerns. For most of the weekend, Pittsburgh’s AQI varied between the purple level, which marks “very unhealthy air” with values between 201 and 300, and the maroon level, which marks hazardous air “of emergency conditions” with values greater than 301.

The primary source of the poor air quality, officials say, was PM2.5, or particulate matter generated by combustion from industrial processes and, of course, wildfires.

Pittsburgh is no stranger to pollution. The city’s legacy is blurred by smog — so much so that it was once famously dubbed “hell with the lid off.” Despite clean-up efforts in recent decades, the Steel City still ranks among the most polluted regions in the U.S. in regard to year-round PM2.5. In 2024, it was 26th on the American Lung Association’s list, which is part of the organization’s annual State of the Air report. In 2025, it moved up to 16th. It remains in that place so far for 2026.

Nevertheless, wildfire smoke has made things considerably worse over the weekend — an alarming trend that officials say is on the rise.

“Pittsburgh’s AQI is inherently known to have higher PM2.5 levels, but … the current PM2.5 level is about 30 times what it should be in Pittsburgh,” Poornima said on Friday, when the AQI first climbed into the hazardous range.

A study published in the Journal of the American Heart Association found that exposure to heavy smoke during wildfires raises the risk of out-of-hospital cardiac arrests up to 70%. The risk was elevated among adults 35-64 years old and in communities with lower socioeconomic status.

Previous findings from the same research group noted that wildfire smoke exposure was associated with increased rates of emergency room visits, not just for breathing trouble, but also for cardiac events, including ischemic heart disease, irregular heart rhythm, heart failure, pulmonary embolism and stroke. 

Emergency room visits increased 42% for heart attacks and 22% for ischemic heart disease within a day of exposure to dense wildfire smoke. The increase was most notable for adults age 65 and older, according to the study.

Poornima says that the impact of poor air quality is greater with prolonged exposure — multiple days or even weeks of poor air quality can add up and cause compounding effects. However, she adds that acute exposure — just a day or two of poor air quality — combined with hot, humid temperatures can cause respiratory and cardiac problems, even for folks who are otherwise healthy. 

With an uptick in poor air quality days, health officials urge the public to listen to their bodies — and to talk about concerns with their doctors before they become problems.

“As a healthcare provider, environmental exposure should be considered in assessing risk for heart disease, and patients should be routinely counseled on this — especially with the higher frequency of days with high levels of air pollution that we have been experiencing,” she adds.

According to the American Heart Associations, there are a few signs and symptoms folks should be on the lookout for, whether you have underlying heart or lung conditions or not. Poornima encourages people to call 911 if they experience: 

• Chest discomfort. Most people having a heart attack feel discomfort in the center of the chest. It can last more than a few minutes, or it may go away and then return. It can feel like uncomfortable pressure, squeezing, fullness or pain.
• Discomfort in other areas of the upper body. Symptoms can include pain or discomfort in the:
  • Arms (one or both)
  • Back
  • Neck
  • Jaw
  • Stomach
• Shortness of breath. This can happen with or without chest discomfort.
• Other possible signs include:
  • Breaking out in a cold sweat
  • Nausea
  • Rapid or irregular heartbeat
  • Feeling unusually tired
  • Feeling lightheaded

The dangerous air brought numerous closures to the region; Kennywood, Sandcastle and Idlewild & Soak Zone closed on July 17, and while Picklesburgh went on as expected, crowds were a bit sparse during peak hours, and many attendees could be seen wearing masks or respirators.

The decision to close down outdoor activities was a good one; Poornima says the best way to stay safe during poor air quality days is to stay indoors, especially if you have any underlying medical conditions.

“While these types of wildfires and the extent of their smoke reach can’t always be predicted, protecting yourself and your family from poor air quality throughout the year is something to consider,” she says. 

In the American Heart Association’s 2020 scientific statement on air pollution exposure, the organization says one of the most effective ways to mitigate the damages done by pollutants is to use portable air purifiers, which have been shown to reduce indoor particulate matter by as much as 50-60%.

“Given their modest upfront cost — $50-200 — and potential benefits in reducing cardiopulmonary outcomes, this measure has a high benefit for the cost,” Dr. Poornima says. “Exposure to lingering wildfire smoke can be extremely harmful and should not be taken lightly. Protect yourself and stay alert.”

If the smoke returns later this summer, healthcare officials advise everyone to take the following precautions:

• Stay indoors with doors and windows closed.
• Use high-efficiency air filters in air conditioning systems or portable air cleaners.
• Avoid exertion.
• Keep well hydrated.
• Consider seeking other shelter if your home does not have an air conditioner and it’s too warm to stay inside. 
• Be mindful that your pets may also be affected by the smoke and bring them indoors.