• Ozone injury across the southern United States, 2002-06 

      Rose, Anita K.; Coulston, John W. (USDA Forest Service. Southern Research Station, 2009)
      In the Eastern United States, hourly concentrations of ozone typically range from 30 to 50 parts per billion (ppb), with events that may exceed 100 ppb. Typical exposure levels can cause visible ...