By Maria Hickey, KWMU
St. Louis, MO. – Air quality in the St. Louis area has been unhealthy the last couple of days and is expected to remain that way through the week.
Missouri Department of Natural Resources officials say they've taken several high ozone readings around the region Monday and Tuesday.
Spokeswoman Sarah McMichael says there was another spate of high ozone days in late June, making this summer worse than last.
"Last year we had a lot of good weather, lower temperatures, higher wind speeds," McMichael said. "This summer has been very dry and very calm, which is conducive to formation of ozone."
Ozone is created when nitrogen oxide mixes with volatile organic compounds, like gas vapors, and cooks in the sunshine.
Wednesday's air quality forecast is level orange. Those with asthma, children and the elderly should limit outside activity.