While petrochemical air pollution in Houston is decreasing, industry there still is underestimating the amounts of reactive chemicals released into the air that lead to ground-level ozone problems, according to a new study by a team of scientists at the Cooperative Institute for Research in Environmental Sciences, a joint institute of the University of Colorado at Boulder and the National Oceanic and Atmospheric Administration. Image of WD-P3 on the tarmac in Houston courtesy of CIRES. (Credit: Bill Dube/NOAA)