A seven-county area in southeast Michigan now meets federal standards for ozone pollution, the U.S. Environmental Protection Agency and the state’s environmental agency jointly announced on Tuesday.
Ground-level ozone, or smog, is not emitted directly into the air but is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight, according to the EPA. Emissions from industrial facilities and electric utilities, car exhaust, gasoline vapors, and chemical solvents are some of the major sources of the components of ozone, which is known to worsen or even cause conditions including asthma, bronchitis, and emphysema.
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) said ozone levels in Metro Detroit have declined significantly since the 1990s, culminating in the recent “attainment” with new, stricter federal ozone standards. The area had previously been considered in non-attainment.
“Ozone attainment is a significant achievement,” acting EGLE director Aaron Keatley said in a statement. “It is a testament to the strides we have made in improving air quality in Michigan’s largest and most industrialized region.”
Annette Switzer, director of EGLE’s Air Quality Division, said regulators will still keep a close eye on ozone levels in the region. “It would be in a maintenance status,” she said. “Which means that even though we're back into attainment status, we have to watch the area very closely and make sure that we are still meeting the standard.” The maintenance plan, which EGLE has submitted to the EPA, includes information about how the state plans to keep the area in attainment, and actions it would take in the event of future non-attainment.
The new designation has some critics among environmental and public health advocates. They include Nicholas Leonard, director of the Great Lakes Environmental Law Center.
Leonard said the region only met standards because regulators agreed to discount some data from the summer of 2022 in Detroit. They attributed high ozone readings there at the time to Canadian wildfires.
And Leonard said air monitoring data taken during the height of the COVID-19 pandemic doesn’t reflect normal conditions. “Any time the EPA designates an area from non-attainment to attainment, it has to demonstrate that what has caused the reduction in pollution levels are essentially permanent and enforceable,” he said. “And we just don't think that's the case here.”
Leonard noted that asthma rates and hospitalizations in Detroit, particularly on the city’s east side, have only increased in recent years. He said groups including his are considering challenging the attainment designation. “I don't think there's any way you can paint this decision other than a pretty serious environmental injustice that's being facilitated by the Michigan Department of Environment, Great Lakes and Energy, and the EPA,” he said.
EGLE’s Switzer disagreed. “Based on the years of data that we were looking at (2019-2022), and also based on the evaluation of our staff that are experts in air quality regulations, it's demonstrated that we are meeting the standard,” she said. “Moving forward with re-designation is the right next step for southeast Michigan.”
Switzer added that EGLE has proposed a new air monitoring station in northeast Detroit, near a Stellantis auto factory that has received numerous state environmental citations, “that will really help to enhance the current network that we have.”
