The greatest risk may for those living be in hot, dry cities such as Los Angeles, which has one of the highest concentrations of ozone. Residents of Los Angeles may face a 25 percent to 30 percent higher annual risk of dying from a respiratory ailment versus people in low-ozone areas such as the Great Plains, the researchers said.
…
An estimated 240,000 people in the United States and 7.7 million people worldwide die of respiratory disease each year, according to data from the World Health Organization. Efforts to reduce ground-level ozone have stalled in recent years, Jarrett said, and now one in three Americans lives in an area that exceeds the national standard for ozone levels.
…
Ozone is also a powerful greenhouse gas, Jerrett said, so measures to improve health might have the added benefit of slowing climate change.