Comparing Day-of-the Week Patterns of Ozone Precursors for Monterrey, Mexico

摘要

The differences between the ambient pollutant profiles of each day of the week were examined at monitoring stations in five regions of the Monterrey Metropolitan Area from 1998 through 2000. Monterrey has been a non-attainment area for meeting the Mexican air quality standard based on one-hour averaged ozone concentration (0.11 parts per million in volume). The average of the days with ozone exceedances is 19 days per year. The air monitoring network has been working since 1992 in the metropolitan area. For each monitoring station, the annual average distributions of each day of the week were constructed using hourly concentrations of CO, NO_X, O3, SO2, and PM10. The results of pollutants and ozone differences provide information in the timing and location of primary emissions. Also, the changes indicate how primary pollutant ratios may play a role in the ozone formation of each day of the week. These data and results can provide additional elements in control strategies for the urban air pollution. Some of the preliminary results indicate that Weekday (Monday-Friday) patterns of NO_X and CO have bigger levels than Weekend (Saturday and Sunday). Lower emissions on weekend produce almost equal peak ozone concentration. In addition, the comparison between profiles indicate that northeast and southwest regions are influenced by industrial emissions and southeast and central regions are affected by vehicular emissions.