Suffocating dome of smoke descends over Philly region

Philadelphia’s jinxed July, which had already featured a record-setting dome of heat and microburst storms that razed hundred of trees, now includes a smothering, suffocating smoke.

The polluted campfire-like vapor from Canadian wildfires plummeted air quality Thursday, lowered visibility enough that flights were delayed at Philadelphia International Airport, and prompted cancellation of a concert at Cooper River Park in Camden County. The Phillies moved Thursday night’s game up one hour due to air quality concerns.

The smoke, which was expected to blanket the region at least through Friday, originated from fires burning in Western Ontario, said Sarah Johnson, a meteorologist at the National Weather Service’s Mount Holly office.

It was swept in by winds that mixed to keep it closer to the ground.

“It’s just a factor of the winds at all levels kind of working together,” Johnson explained.

It is difficult to pinpoint when the air quality might return to normal, she said. Those forecasts come from state environmental protection departments and are usually no more than 48 hours out.

The Pennsylvania Department of Environmental Protection has declared a Code Purple Air Quality Alert for Friday. Code purple signifies very unhealthy air, meaning people should avoid long or intense outdoor activities, and sensitive groups should avoid all outdoor activities. The department suggested not using gas-powered lawn and garden equipment, and avoiding the burning of leaves or trash.

Rain forecast for Saturday could help suppress the smoke, Johnson said, but on Thursday afternoon it was too early to be sure.

Poor air quality caused by the fires remained the biggest issue as they burned through forests and buildings before their smoke swept south, collecting ambient pollution from Boston, New York, and other areas before reaching Philadelphia.

Philadelphia issued a Code Red Air Quality Caution Day on Thursday, meaning some people were at risk of experiencing health effects, including elevated risks for people with heart or lung disease, asthma, older adults, children, pregnant people, immunocompromised people, people experiencing homelessness, people who use drugs, people without access to air filtration, and outdoor workers.

The city advised people to limit their time outdoors and consider rescheduling activities.

“Today is not the day to start your marathon training plan,” Palak Raval-Nelson, commissioner of the Philadelphia Department of Public Health, said in a statement.

The smoke affected thousands of square miles in the region, from the Poconos to the Shore through Delaware.

The Air Quality Index, or AQI, by the U.S. Environmental Protection Agency was in the unhealthy range for all of the region as of 4 p.m. Thursday. The index ranges from 0 to 500. Unhealthy is from 151 to 200.

Censors in Centre County, Pa., recorded a hazardous AQI of 345 by Thursday afternoon, the highest and most dangerous level. Other sensors in Lycoming and Bradford Counties recorded AQIs above 200, or very unhealthy.

Center City had an index of 192, which is considered unhealthy. Northeast Philadelphia, Chester, Norristown, and Camden all were similarly in the unhealthy range.

Not helping: Temperatures in the 90s with humidity so high that it made it feel in excess of 100 degrees.

Julie and Bill Guise, 66 and 72, respectively, basked in the somewhat cool breeze billowing from a giant fan inside the President’s House complex at Independence National Historical Park, hoping to get relief from the oppressive air. The Flagstaff, Ariz., residents, however, were unaware of what exactly was causing it.

“We couldn’t figure out what it was,” Bill Guise said of the haze in the atmosphere.

But it did not change their plans. The couple are used to wildfires.

“It’s much worse out West,” Julie Guise added, likening the western smoke, when it’s extra bad, to sitting next to a campfire.

Eric Balaban, a pulmonary and critical care fellow at Temple University, was hesitant but still went running Thursday morning.

“If I didn’t have an addiction to running, I would not have gone. And I would recommend other people not to run. Do as I say, not as I do,” he said with a laugh.

But exposure to the smoke is a serious matter, Balaban said. He noted that the smoke that travels “carries a uniquely toxic profile that poses severe health risks to both healthy individuals and vulnerable populations.”

Ruth McDermott-Levy, a professor at Villanova University’s school of nursing, said that air quality had become a risk not only for those already suffering from health issues, but for everyone.

“All of us are at risk,” McDermott-Levy said. “Certainly there are groups of people at greater risk, from pregnant women, children, older people, and those with cardiac and respiratory illnesses. But we’re at an unhealthy level for everyone.”

The two major pollutants of concern are ground-level ozone and fine particulate matter known as PM2.5.

Ground-level ozone is a pollutant that forms when nitrogen oxides and volatile organics emitted by vehicles, power plants, and industry react in sunlight, especially during hot days. It can cause airways to constrict, leading to shortness of breath. It can especially affect those with asthma, emphysema, and chronic bronchitis.

Fine particulate matter is so small that it can cross from the lungs directly into the bloodstream, bringing a body-wide exposure that can increase the risk of heart attacks and strokes, in addition to causing acute chest tightness, shortness of breath, and dizziness in otherwise healthy people.

Staff writer Nate File contributed to this article.