Air pollution

Clean air is clear and has no bad smell, so you can see faraway mountains through it. Smoke and dust from cars, factories and burning rubbish make the air polluted: it turns the sky grey, stings the eyes and makes people cough, and it harms animals and plants too. Walking, taking the bus, planting trees and never burning rubbish keep the air cleaner, and on a very smoggy day it is best to stay indoors.