St. Louis is under the year’s first air quality alert for ozone.
The St. Louis Clean Air Partnership issued the alert, which says the St. Louis region is forecast to see an orange level, unhealthy for sensitive groups, for much of Tuesday.
The region could see levels of ozone that are dangerous for children, older adults and people with respiratory diseases such as asthma.
“It's definitely a cautionary tale about being mindful of how much exertion you do outdoors today, especially in the peak hours, say 10 to 7, but even more so in the late afternoon,” said Susannah Fuchs, who works for the American Lung Association in St. Louis.
Ozone is a clear air pollutant that forms because of emissions from power plants, industrial plants, gas cars and lawn mowers.
On hot, sunny days with less wind, like Tuesday, ozone is more likely to build up in the lower atmosphere, where people might breathe it in.
Ozone levels have been improving in St. Louis in the past few decades, but the region is not in compliance with the Environmental Protection Agency’s limits.
“There's a lot of variation, but we have, on the whole, been going down on the number of days that have had exceedances of the standard,” said Carol Lawrence, manager of environmental services at the East-West Gateway Council of Governments. “But we still are having them.”
St. Louis, St. Louis County and St. Charles all got F grades for ozone pollution in the American Lung Association’s most recent annual report. Last fall, the EPA upgraded St. Louis’s nonattainment level to serious, one level worse than its earlier status.
To stay safe, experts recommend people avoid exercising outdoors when ozone levels are high.
“Not going out running at 4 o'clock on an orange air quality day would be a good idea, for example,” Fuchs said. “So plan around it, know what the air quality forecast is, know what your risk factors are.”
To improve ozone levels in St. Louis, people will need to reduce emissions from cars, promote public transportation and put controls on industry and power plants, according to the East-West Gateway Council of Governments, which monitors ozone data in the St. Louis region.
“There's a lot of things that the average person can do to help reduce ozone,” said Mary Grace Lewandowski, director of community planning at East-West Gateway.
The Clean Air Partnership and Citizens for Modern Transit are also launching a campaign this week urging St. Louisans to ride public transit during the summer to prevent ozone pollution. The campaign is called “No Red Days,” referencing the air quality scale that is one level higher than Tuesday’s ozone forecast.
“We did not time it to launch with this first orange air quality forecast, but it sure worked out well,” Fuchs said.
The organizations are also giving out free metro transit day passes to use this summer.
