S - We needed to get some evidence of why Air Quality was poor on the local streets outside the school, partiularly in the mornings. We wanted this evidence to prove to students and parents the environmental impact of their travel choices. T - We set up a Citizen Science experiement to test levels of Particulate Matter, to look for Nitrogen loving/Nitrogen sensitive types of Lichen and to look for Tar spots on sycamore trees as natural indicators of Air Quality at various locations around our schools. A - The students set up the expeiments in various locations including at the school gates, on Ruislip Road East and in the playground and recorded their results in teh project portfolio. R - They found higher levels of Particulate Matter the closer the distance to the road, multiple example of Nitrogen loving Lichens and no Nitrogen Sensitive Lichens meaning that Nitogen levels must be high, especially on the main roads on 2 sides of the school.