There have been more ozone alert days in the Oklahoma City area this year than ever before. But even though that doesn't mean air quality is getting worse here, it does still mean you can get a free ride to work Friday.
The 19 ozone alert days so far this year replaced the old record, officials said. The first was May 18 and the most recent was Sept. 5, according to the Association of Central Oklahoma Governments.
But a primary reason for the high number is the changing standards for ozone alert days, said Curt Goeller, an environmental program specialist with the state Environmental Quality Department.
Oklahoma City's air quality has improved steadily along with the rest of the country's since the passage of the Clean Air Act in 1970, but the federal Environmental Protection Agency continues to toughen air quality standards.
“Everything has just continually gotten better. But our knowledge on how our bodies are sensitive to air pollution has improved as well,” Goeller said. “That's why they continue to make the standards more stringent.”
What is ozone?
Ozone is the same substance that forms the protective ozone layer in the upper atmosphere. But closer to the Earth's surface, it does harm, not good.
“When we talk about ozone, we're talking about smog,” said Ryan Baker, the government association's special programs officer.
Roughly half of the pollutants that cause smog in central Oklahoma come from internal combustion engines on everything from trucks to lawn mowers, Baker said.
But despite sending pollutants in the air, they aren't as bad as they once were.
“A lot of things have happened with our automobiles to make them a lot cleaner than they used to be,” Goeller said.
What is an alert day?
An ozone alert day is declared whenever the pollution rises to a level that can have adverse effects on children, seniors, people with respiratory illnesses and people who work outside for prolonged periods.
Hot, still days make it worse, so it's no surprise the last two summers in Oklahoma have produced quite a few alert days in the metro area.
“There's normally a high pressure system sitting on top of us (in extreme heat), which means not much wind, no mixing to speak of, no new air coming in, and air pollution just gets that much worse,” Goeller said.
Air quality improvement is tied to federal funding grants related to air pollution. Cities have to either be in compliance with federal air quality rules or have a sound plan to reduce air pollution in order to keep receiving the funds.
Central Oklahoma's plan has proved to be in line with what federal officials want so far, despite the high number of ozone alert days this year, Baker said.
Free bus rides Friday
As part of local efforts to combat poor air quality, Metro Transit is offering its final free ride day of the year Friday. Anyone can ride Metro Transit buses on any route at any time Friday for free.
Officials have said Metro Transit's free rides program is intended to help reduce pollution by getting more people to share a ride and to increase ridership.