TOAR shows present-day global ozone distribution and trends relevant to health; public database
Green Car Congress
FEBRUARY 6, 2018
Ozone levels across much of North America and Europe dropped significantly between 2000 and 2014. Even so, during 2010-2014, people in parts of California, Arizona, Colorado, Texas, the Midwest and the Middle Atlantic still experienced more than 15 days a year in which ozone levels exceeded the US health-based air quality standard of 70 parts per billion (ppb) averaged over eight hours. Trends in daily maximum ozone levels (known as 4MDA8) at urban and non-urban sites.