The MPCA has issued an air quality alert for September 14 for ozone and fine particles.
Particles, most of us get: they’re the haze you can see in the air. But what is ozone? And why does it need an alert — isn’t ozone supposed to be a good thing?
What is ozone anyway?
Ozone can be good or bad, depending on where in the atmosphere it’s found. You’ve probably heard of the “ozone layer” in the upper atmosphere — up there, ozone is a good thing, as it protects us from harmful ultraviolet (UV) radiation from the sun. But down here, where we live and breathe, it’s called ground-level ozone. And having too much of it can be harmful to human health.
Ozone is a gas composed of three atoms of oxygen (O3). In the upper atmosphere it comes from natural and man-made sources. The ground-level type we’re concerned about is not emitted directly, but is created when oxides of nitrogen (NOx) and volatile organic compounds (VOC) cook in sunlight.
To help distinguish “bad” ozone from “good” ozone, remember: “Good up high, bad nearby.” Today’s Air Quality Index is in the orange zone, meaning the air is unhealthy for sensitive groups.
Ozone is most likely to reach today’s levels on hot sunny days in urban environments, but can still be high during colder months. It can also be transported long distances by wind, so even rural areas can experience high ozone levels. People most at risk from elevated ozone levels include those with asthma, children, the elderly, and anyone working or playing hard outdoors. To protect yourself, stay indoors with air conditioning if possible, and if you need to be outside, take it easy. If you experience respiratory symptoms, use your inhalers as directed and contact your health care provider. To learn more about ozone, visit https://www.pca.state.mn.us/air/ozone.