Hundreds of thousands of Americans across four states are waking up to a dire warning to stay indoors because the air outside is hazardous to breathe.
Pollutants reached 'unhealthy' levels for residents in Pennsylvania, Georgia, Alabama, and Oklahoma on Monday morning, officials said.
An air quality tracking system from the US Environmental Protection Agency (EPA) detected an extremely hazardous pocket of polluted air around the Pittsburgh suburbs, just ten miles south of the Pennsylvania city.
Live data captured sharply elevated levels of PM2.5, microscopic particles composed of toxic compounds or heavy metals that are small enough to penetrate the lungs, exacerbate respiratory issues such as asthma, and contribute to heart attacks.
In the South, a 110-mile swath across eastern Oklahoma has been declared unhealthy by the EPA, and a 127-mile-long pocket centered over Columbus, Georgia, is dealing with highly polluted air Monday morning.
The increased levels have been linked to recent wildfire smoke, which exacerbates a condition called stagnant air, where little to no wind and high atmospheric pressure trap pollution near ground level.
Air quality levels are measured on a scale from 0 to 500: good (0–50) carries little risk, moderate (51–100) may affect sensitive individuals, unhealthy for sensitive groups (101–150) poses increased risk and unhealthy (151–200) impacts everyone, limiting outdoor activity.
In Glassport, Pennsylvania, the Air Quality Index (AQI) reached 192, while readings in parts of Oklahoma, Georgia, and Alabama exceeded 150.
To understand the impact of stagnant air on cities, it is helpful to look at atmospheric pressure. Pressure is measured in millibars, with normal sea-level pressure being 1,013 millibars.
Anything between 1,015 and 1,020 millibars is considered a high-pressure system, with strong pressure exceeding 1,030 millibars, especially in the winter.
In Glassport, the air quality-tracking website IQAir reported that pressure reached 1,031 millibars Monday morning, causing sinking air from above to warm and compress as it descends.
Stagnant air means the air around you is barely moving, like it's stuck under a lid, so pollution, smoke, car fumes, and other particles can't blow away or mix higher up in the atmosphere, causing them to build up near the ground where we breathe.
While the AQI directly over Pittsburgh has remained at 'moderate' levels, the entire region of western Pennsylvania is under a high-pressure system that is trapping more pollutants than usual.
The National Weather Service has officially issued an air quality alert for Allegheny County, stating that a 'code ORANGE' was in effect in Clairton, Glassport, Lincoln, Liberty, and Port Vue.
'A code ORANGE air quality alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, the elderly, and people suffering from asthma, heart disease, or other lung diseases,' NWS stated.
Near Columbus, a city with over 200,000 residents, smoke from multiple fires in both Georgia and Alabama is being carried north by the wind, increasing local pollutant levels.
The worst readings were recorded near Eastaboga, Alabama, where IQAir reporting stations recorded an AQI of 170 and PM2.5 levels 16.6 times the World Health Organization's recommended safe limit.
The EPA has warned that all Georgia residents between Lagrange and Fort Gaines are in hazard zone for high levels of PM2.5.
Residents in the affected areas have been advised to avoid outdoor exercise, wear a face mask if going outside, close all windows to prevent polluted air from coming inside, and turn on air purifiers if you own one.
Even short-term exposure to high levels of these particles can cause concerning health problems, including irritation of the eyes, throat, and nose.
Among vulnerable individuals, inhaling particles from smoke, car exhaust, and factory emissions can also cause irregular heartbeats, asthma attacks, coughing, chest tightness, and shortness of breath.
