Healthy Air

Colorado’s Front Range got lucky with fewer ozone days in 2023

More action needed to reliably protect public health from harmful air pollution

Clean air

Haze visible over downtown Denver as seen from Red Rocks.

How many ozone alert days did Colorado have in summer 2023?

It’s true that the Front Range experienced fewer ozone alert days during the May 31-Aug. 31 ozone season in 2023 than in recent years — 37 alerts, which was the lowest since 2019. But that still meant 26 days when ozone concentrations in our air exceeded Clean Air Act standards, or 28 percent of the time.

Steps aimed at cutting the emissions that form ground-level ozone, such as free ozone season transit and encouraging Coloradans to shift away from highly-polluting gas-powered lawn equipment, may be starting to have an impact. But it was also an unseasonably wet and cool summer on the Front Range, which meant less opportunity for ozone concentrations to spike to unhealthy levels since ozone forms in the presence of sunlight and the chemical reaction occurs more quickly at higher temperatures.

Exposure to elevated ozone levels can cause harmful health effects including lung damage, worsening of existing respiratory conditions such as asthma, and even cardiovascular disease.

In a Denver Post article, CoPIRG Clean Air Advocate Kirsten Schatz offered this commentaray:

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