2. Alvarado,Cappelletti,Puglisi,Ferrari,Kudhoos

7. Air pollution is changeable and there are many different air pollutants contributing to it. Once pollutants are released into the air, they interact with each other and the environment in complex ways depending on temperature, humidity and other environmental conditions.

8. Pollutants can be categorised into two groups: Primary pollutants – which come from human processes Secondary pollutants – which are from the interaction of primary pollutants with the atmosphere