One major pollutant of concern is in the Mexico City Metropolitan Area (MCMA) is tropospheric ozone. It is a secondary pollutant that damages local vegetation and the human respiratory system. Ozone is formed in the atmosphere by nitrogen oxides (NOx) and volatile organic compounds (VOCs), but it... Show moreOne major pollutant of concern is in the Mexico City Metropolitan Area (MCMA) is tropospheric ozone. It is a secondary pollutant that damages local vegetation and the human respiratory system. Ozone is formed in the atmosphere by nitrogen oxides (NOx) and volatile organic compounds (VOCs), but it is unclear which of these two is the limiting reactant. Finding the limiting reactant would allow legislators to take proper measures to control ozone concentrations. The weekend effects of ozone, NOx, and CO (an indicator for VOC) were analyzed from 1986-2003. It was found that though there was a definite normal weekend effect for NOx and CO, there was no consistent weekend effect for ozone. This made it difficult to pinpoint the limiting reactant of ozone formation. The CO/NOx ratio was then calculated to study possible correlations with ozone concentration. There was a positive and almost linear relationship between ozone concentration and the CO/NOx ratio. This means that as CO (VOC) increased, ozone concentrations increased as well. Next, bivariate correlations were performed and they gave a good and positive relationship for CO/NOx ratio and ozone concentrations. However, there was no clear relationship between ozone concentration and PM10, and ozone and SOâ. Finally, the calculated ozone sensitivity coefficient showed that in the MCMA, ozone concentrations were usually VOC sensitive. This clarifies the limiting reactant of ozone formation and shows that limiting VOCs would cut down on tropospheric ozone concentrations. Show less
