Galveston County Daily News July 11, 2007 TEXAS CITY - Ozone, an air pollutant that forms when nitrogen oxides and volatile organic compounds are heated by sunlight, has regularly reached high levels at Galveston's Scholes International Airport, said a professor during a trade union meeting this week. Representatives from at least 10 unions met in Texas City on Monday with Jonathan B. Ward Jr., professor and director of preventive medicine and community health at the University of Texas Medical Branch.