Allard added that children and people who have asthma or other lung conditions are most at risk from high levels of smog air pollution. County stations have already recorded more exceedances of standards this year than were recorded in all of 1999, the cleanest year on record for the county. We experience high smog levels as late as October some years. Ozone, the primary component of smog, is formed when hydrocarbons and nitrogen oxides react chemically in the presence of sunlight.
Ozone damages human lung tissue, manufactured materials, and crops.
It forms much more quickly at higher temperatures.