Extreme Heat Chips Away at Effectiveness of Ozone Air Standards

Unrelenting heat waves are boiling cities across the U.S. this summer, spiking ozone pollution levels and threatening the fighting power of air quality safeguards.

Regulations that limit ozone-forming emissions, which migrate into pollution-burdened areas like the coastal Northeast states, have improved air quality since being implemented in the 1970s. But some experts worry that hotter temperatures wrought by global warming could curtail the ability of current rules to limit heat-nourished ozone to health-protective levels.

“The atmosphere is getting supercharged, and the chemistry that makes ozone is going along with it,” said Paul Miller, executive director of the Northeast States for ...