Ozone gas (O3) is formed when nitrogen oxides react with sunlight.
Stratospheric Ozone, which is 10 to 15 miles above the earth's surface, is essential to life because it filters harmful ultraviolet radiation from the sun, reducing the amount reaching the earth's surface.
In cities where it is very sunny and very polluted, photochemical smog can get so bad; children are sometimes kept away from school!
Plants and trees use up carbon dioxide and therefore help to 'clean' the air.
Lichens can provide a simple and effective way of establishing the degree of pollution in a given area.
VOC stand for Volatile Organic Compounds and are air pollutants that evaporate easily.
As long ago as 1273, coal was first banned in London, because it could be bad for your health.
The word 'Bonfire' comes from the medieval term 'bone fire' - when animal bones were burnt in the street.
In one year, a car an produce 4 times its own weight in carbon monoxide.
Children are particularly vulnerable to air pollution - they breathe faster than adults and inhale more air per pound of body weight.
People travelling by car can be exposed to higher levels of pollution than pedestrians or cyclists.
Cycling can reduce the risk of heart disease, reduce stress and increase life expectancy.
During term time, 20% of traffic in rush hour is related to children being driven to school.
There are more than 26 million vehicles licensed to use UK roads.
It would take 20 of today's new cars to generate the same amount of air pollution as one mid-1960s model car.
Service delivery vehicles spend 20-60% of their time idling, which costs fleet owners a lot of money and gets them nowhere.
Added weight makes your car's engine run less efficiently, increasing air pollution.
The sun is estimated to be 4.6 billion years old and 150 million km (on average) away from Earth.
Starting a car cold increases trip emissions compared to starting the car warm.
For a 5-mile trip, starting the car cold generates about 30 percent more nitrogen oxide and 60 percent more carbon monoxide than starting the car when it is warm.
Scientists predict that around the world, average temperatures could increase by anywhere from 1.4 to 5.8 degrees Celsius over the next 100 years. To understand what this means think about the fact that today's average global temperatures are only about 5 degrees warmer than they were during the last Ice Age about 18,000 to 20,000 years ago.
Greenhouse gases are an important part of the Earth's atmosphere. They help warm the Earth, without them the Earth's average temperature would be -18 degrees Celsius! The problem is that the burning of fossil fuels creates more greenhouse gases than the planet needs.