Individually, our cars, lawnmowers and refueling habits aren't the culprits in ozone pollution. It is the cumulative effect of all of these in an urban area that can be responsible for either producing or reducing ground-level ozone. If everyone does just a little bit every day towards reducing emissions, we can all enjoy the benefits of clean air. Ground-level ozone is a problem anywhere it exists. Typically, it is produced in urban areas where there are lots of cars, industry and other sources of combustion.
Ozone can travel with the wind to other places and become a problem there too.
In the tropics, where forests are slashed and burned to create farmland, all of the ingredients needed to produce ozone are there. So, as you can see, ground-level ozone is not just a local problem. It is a global problem. During the summer months, when it is hot and the days are longer. Here, in North Carolina, the period of May through September is considered the ozone season.