On your daily walk or exercise, think about where air pollution might be higher or lower in your local area, remembering that pollution is often invisible.
Trees and hedges can block air pollution, and wind direction can play a role.
Print a large scale copy of a local map and use dots or emojis to annotate it representing where you think you will find higher, middle and lower levels of local pollution and reasons why that might be. Will time of day be a factor? You can source local maps from Google Maps or Digimap.
Investigate levels of air pollution further by creating pollution catchers. Make holes in paper plates or pieces of card, cover them in Vaseline or chapstick, and hang them up in different areas to catch pollutants in the air for a number of days.