The wind speed plays a role in diluting pollution. It determines how quickly the pollutants mix with the surrounding air and how fast they move away from the source. Strong winds tend to lower the concentrations by spreading the particles further apart as they move downstream. This process is known as dispersion. Swirling, turbulent air (eddies) help mix the pollutants with the clearer surrounding air.
However, wind speeds can also contribute to the amount of pollutants in the atmosphere. High winds can cause dust to be picked up and enter the air.
Source: Wikipedia