Three cities in the Bay among the most polluted in the United States, according to a report

Nearly half of Americans currently live in places with unhealthy air, and the metropolitan area of the Bay Area is among the top 20 with air quality, according to a report by the American Lung Association. The 26th annual “State of the Air” report published last night shows that 46% of U.S. residents are affected by poor air quality. In the list of most ozone-contaminated metropolitan areas, San Jose, San Francisco and Oakland rank 14th national…