- Metro Detroit faced hazardous air quality due to fireworks and stagnant weather, with PM 2.5 levels reaching 579, well beyond the AQI limit of 500.
- Conditions improved slightly by late morning, but air quality remained unhealthy, with PM 2.5 levels near 200.
- Increased wind and rain are expected to gradually improve air quality, but sensitive groups should remain cautious.
Extremely poor air quality hung over most of metro Detroit this morning, resulting from pollution from last night’s fireworks and a stagnant weather pattern that kept pollution at ground level.
The government air monitoring website airnow.gov showed PM 2.5 or fine particulate matter levels rising to 579 at 12 AM, a level identified as “beyond the AQI.” The Air Quality Index, from 0 to 500, identifies pollution levels above 301 as “hazardous” and a “health warning of emergency conditions: everyone is more likely to be affected.” By late morning, airnow.gov showed PM 2.5 levels were still close to 200 or “unhealthy.”
Last summer, when wildfire smoke from Canada covered much of the eastern U.S., Detroit was said to have the “worst air quality in the world” after the AQI rose above 200.
Short-term exposure to fine particulate matter is associated with increased infant mortality, heart attacks, strokes and hospital admissions for COPD or asthma attacks. Nationally, the number of days the government’s Air Quality Index labels as “very unhealthy” or “hazardous” have increased dramatically in the last decade, a change largely attributable to PM 2.5 from wildfires.
In addition to PM 2.5, fireworks produce significant amounts of sulfur dioxide, carbon monoxide and metals like aluminum and cadmium.
The pollution from this year’s Fourth of July celebrations was “far above typical,” according to Jim Haywood, senior meteorologist for the Michigan Department of Environment, Great Lakes and Energy’s Air Quality Division.
“The culprit is dead calm winds, even up to nearly 3,000 meters above the ground,” he wrote in his air quality forecast. “As a result, the smoke from the Thursday evening firework shows is just sitting and not dispersing.”
Increasing wind and rain showers were expected to slowly clear the air in Southeast Michigan on Friday. Still, Haywood predicted the AQI would remain above 100 or the “unhealthy for sensitive groups” range for the rest of the day.
Although fireworks are likely to continue over the weekend, he said that higher winds on Saturday should help reduce PM 2.5 concentrations, although winds could decrease on Sunday.
Last year, the company JustAir, which has air monitoring networks in cities including Detroit and Grand Rapids, observed extremely high levels of PM 2.5 pollution around the Fourth of July in Grand Rapids. While the city also saw periods of poor air quality from the Canadian wildfires, the days around July 4 were still some of the worst for PM 2.5.
The American Lung Association recommends that those with asthma watch fireworks from a distance, stay upwind of smoke, go inside if it’s too smoky and keep a rescue inhaler on hand.
Michiganders can check on their air quality at airnow.gov, or via neighborhood monitors offered through JustAir’s app or PurpleAir’s online map. The government site is considered the gold standard in terms of accuracy, but private monitoring networks can give a more localized picture of air quality. If pollution levels are high, experts advise staying indoors in air conditioning and wearing an N95 of KN95 mask outdoors.