Hydrocarbons and nitrogen oxides are the two primary precursors for summertime ozone production. While state and federal agencies have focused recent efforts on controlling nitrogen oxides, there is less known about the effect of hydrocarbon concentrations on ozone production. A recent study published by Sonoma Technology Inc. provides evidence that ozone production in this region may be driven more by hydrocarbons than by nitrogen oxides.
In a report issued by the American Lung Association in June 2000, the Rock Hill-Charlotte-Gastonia metropolitan area was identified as the 8th worst U.S. urban region for summertime production of ground-level ozone. Ozone adversely affects respiratory health. In the Carolinas, a large number of emergency room visits for respiratory difficulties are directly attributable to high ozone levels that occur during the summer. In April, 2000, the Charlotte Observer identified summertime ozone production as the most critical environmental issue facing the Central Carolinas region. Summertime ozone levels have significantly risen over the past five years. In a research presentation by Winthrop chemistry student Jenny Perry to the NC DAQ last August, the rise in ozone production was correlated with increases in traffic and growth in the region. Jenny also found that, over the past decade in this region, there has been surprisingly little difference in summertime ozone weekday/weekend levels.