Number of ‘Unhealthy’ Air Days Down 74% in California

In 2011, California had about 74% fewer days of "unhealthy" air levels than in 2000, according to a report by the California Air Pollution Control Officers' Association. The report found that since 1980 ozone pollution has dropped statewide and that there have been smaller reductions in particulate matter emissions.

• "Report Finds Fewer Unhealthy Air Days in California" (Yeung, California Watch, 4/20).