The reason Cincy's air is bad? It's summertime, and the ozone is baking

Anne Saker | Cincinnati Enquirer

Show Caption Hide Caption What is ozone and how can it harm you? Ozone alerts and warnings are common during the summer in Cincinnati. Here's an explanation of ozone's health effects and what you can do about them.

Summer weather turns Greater Cincinnati's air into a hazard.

Stagnant, still, cloudless hot weather clapped itself on top of the region and cooked up a steamy layer of ozone through the weekend and into Monday.

Storms, rain and cooler temperatures are expected to roll through Tuesday afternoon, and the slowly changing weather persuaded officials to end the ozone advisory Monday. But the cautions remain for the young, the old and people with respiratory issues: Be careful breathing the soupy air.

“For those who are sensitive, plan your days accordingly,” said Anna Kelley, monitoring and analysis supervisor at the Southwest Ohio Air Quality Agency. Kelley also pointed out that with the region in a river valley belted by two major interstates, Greater Cincinnati is a topographic laboratory for poor air quality.

In fact, the 2018 annual study on air quality from the American Lung Association grades Cincinnati with an F for ozone pollution. The group's report did note the city's getting better in trying to reduce the particulates that turn into ozone pollution.

Considering the region endured the warmest May on record, and June also has been toasty, the experts said it’s likely the region can expect more summer days with nasty air quality. Thursday's solstice marks the official start of summer.

“In the summertime that we’re entering, there’s a large area of high pressure, and it contains stagnant air in circulation around the high with light winds, which is not allowing a lot of mixing to occur,” said meteorologist Brian Coniglio of the National Weather Service in Wilmington. “So any air pollution stays within the air mass and is not flushed out by any strong winds.”

The No. 1 pollutant this time of year is ozone, but it’s not the same thing as the ozone layer in Earth’s atmosphere. Ozone pollution is a ground-level stew of dust, exhausts and gases from cars, power plants, industrial facilities and other sources. The steady sunlight cooks it all together into a breathing hazard.

The air-quality agency issued its first ozone-pollution warning this year on May 25, the earliest ever, said agency spokeswoman Joy Landry. Ozone pollution can aggravate a host of physical problems by triggering coughing, inflaming the airways and lungs, and bringing on asthma attacks.

Over the weekend, a warm-air mass parked itself over Greater Cincinnati, the winds died off, and the rain was light and widely scattered – a classic situation for ozone pollution to boil up. The numbers were troubling enough Friday to warrant the air quality agency to issue weekend warnings for the region, which covers Butler, Clermont, Hamilton and Warren counties in Ohio and Boone, Campbell and Kenton counties in Kentucky.

Every day, the air-quality agency takes measurements in 11 stations around the region in the early afternoon to rate the issues in the atmosphere. Kelley said the pollution numbers dropped slightly Sunday, and they moved Monday on the same trend for the rest of the week.

Coniglio of the NWS said the week's forecast calls for highs back in the low 80s by Thursday. “Plus, we may see some showers, which would scour some of the pollutants from the air," said Coniglio of the weather service.