Clean air?

Clean air? The earth is surrounded by a mixture of gases called the atmosphere. The atmosphere is made up of… 1.4% 20.6% 78%

It wasn’t always like this… 4.5 billion years ago.

4.5 billion years ago… Earth was a very violent place It was just a ball of molten (hot) rock and minerals. Very volcanic, which released gases into the atmosphere The atmosphere was mainly Carbon dioxide Water vapour Nitrogen

4 billion years ago.

4 billion years ago… The earth is cooling down Water vapour from the atmosphere condenses into oceans The atmosphere was mainly Carbon dioxide Nitrogen

3 billion years ago.

3 billion years ago… The first plant life appears Algae appear on the water, and start to photosynthesise (make their food from sunlight) This makes oxygen which goes into the air The atmosphere was mainly Nitrogen Carbon dioxide Oxygen

2 billion years ago.

2 billion years ago… Proper plants evolved There is more photosynthesis happening This uses up more of the carbon dioxide and makes more oxygen which goes into the air The atmosphere was mainly Nitrogen Oxygen Carbon dioxide

Today!

Today… Plants use up carbon dioxide from the atmosphere and add oxygen People and animals use up oxygen and make carbon dioxide People are cutting down trees a lot more – what do you think this will mean for the amount of carbon dioxide and oxygen? The atmosphere is now Nitrogen (79%) Oxygen (20%) Carbon dioxide and other gases (1%)

Complete the table using the information on the screen: Time Main Events Atmosphere 4.5 billion years ago Earth formed. Violent volcanic eruptions. Carbon dioxide Water vapour Nitrogen 4 billion years ago Earth cools Water condenses to form oceans. 2.5 billion years ago Algae grow and begin to carry out photosynthesis. Oxygen 2 billion years ago Plants grow – pollute air with oxygen and remove carbon dioxide. today Humans can live on Earth Nitrogen (79%) Oxygen (20%) Carbon dioxide and other gases (1%)

There are four main types of air pollution: Carbon dioxide Carbon dioxide comes from burning fuels. It is a greenhouse gas and could be helping the earth to heat up (global warming).

Carbon monoxide Carbon monoxide is made when fuels don’t burn properly. It is a poisonous gas, and stops the body from being able to carry oxygen properly.

Nitrous oxides Nitrous oxides are made when fuels burn at a very high temperature like in a car engine. They also help fuels to burn better, which is why racers use NOS in their cars! They cause acid rain and smog, and can damage your lungs, especially if you have asthma. They are also greenhouse gases and damage the ozone layer.

Sulphur dioxide Sulphur dioxide is made when fuels like coal, petrol and diesel burn. These fuels all contain some sulphur, which gets turned into sulphur dioxide. It causes acid rain.

environmental impacts pollutant comes from? environmental impacts carbon monoxide fuels not burning completely poisonous gas, stops oxygen being carried round the body properly nitrous oxides fuels burning at a very high temperature like in an engine acid rain, smog, asthma sulphur dioxide burning fossil fuels that have sulphur in them acid rain carbon dioxide burning fossil fuels greenhouse gas, heats up the earth

Catalytic convertors can help reduce pollution from cars by changing dangerous gases into harmless ones… http://www.youtube.com/watch?v=rmtFp-SV0tY

So why is clean air so important? When making computers, it is very important the air is clean, because the electronic chips are so small. Any dirt or dust could stop the equipment working properly.

People working with microchips have to use a clean room and wear special suits.

In an operating theatre the air has to be very clean – why?

Modern operating theatres are very clean – the air is usually cleaned with lots of filters. This helps to make sure there is no dirt or bacteria that could infect the patient.