|Grade Level:||4th- 7th |
|Time Required:||About 1 day
|Materials:||Readily available |
You need to breathe to stay alive. But how clean is the air you breathe? If you breathe dirty air, you are more likely to develop health problems and become ill. In this experiment we will look at the air particles found in several locations to determine where there is the least amount.
Plants and animals need clean air too. A lot of the things that make our lives more comfortable such as cars, electricity and heating create bad gases which make the air dirty. The problem of air pollution started with the burning of coal in homes and factories. Dirty air is called 'polluted air'.
'Air pollution' is what we say to describe all bad gases in the air that we breathe and that are dangerous for us. But do not worry! Not all gases are bad!
500 years ago in Britain, the burning of coal was increasing in cities like London. Coal was used in factories and also used to heat homes.
Coal, when burnt makes a lot of smoke, which makes the air very dirty.
About 200 years ago, the Industrial Revolution began in Britain. Factories were built, and even more coal was burnt. Air pollution was becoming a really big problem, especially when the weather was foggy. With foggy conditions and light winds the smoke or air pollution covered the whole city, and would not move.
Smoke and fog together create smog.
Smog was a big problem in the winter. Because of the cold weather, more coal was burnt to warm houses and this made more smoke.
When smog was stuck over a city, it became really hard to breathe and see clearly. In 1952, the Great London Smog occurred and more than 4000 people died because of the smog!
New laws were created from this catastrophe in 1956 and 1968, so that it would not happen again. These laws are called the 'Clean Air Acts'.
These laws were made so that air would become cleaner. The laws encouraged people to use less coal or use cleaner coal in their homes and switch to other fuels such as gas. Factories started using tall chimneys so that the smoke would go high up in the sky and no longer cover cities, and new factories built outside cities in the countryside. Smog occurred less often and the air became cleaner.
WHAT IS TODAY'S AIR POLLUTION LIKE?
Have you ever noticed that the air in a city smells different from air in the country? One of the reasons is that exhausts from vehicles give off fumes, or gases, which can poison you.
Today, when we think of air pollution, we should think of transport, especially cars. Today there are about 23 million vehicles on the road in Britain, and 20 million of them are cars! The fuel they use - petrol and diesel - releases a lot of pollution in the air.
The car exhausts eject a lot of bad gases, which create air pollution. These gases can be very dangerous for children. Although the fuels are becoming cleaner, it will not be making that much difference because there are more and more cars.
There is less pollution from coal, but today's modern world still creates air pollution. Today, air pollution has not really fallen, because new bad gases are released in the air, and there are a lot of them.
Transport is not the only reason why we have air pollution. Factories also release bad gases in the air, even with the 'Clean Air Acts', it still causes a lot of air pollution. This air pollution that they make is the main cause of acid rain.
WHAT ARE THESE BAD GASES?
Gases from vehicles:
Carbon monoxide is a gas that pollutes the air, and is mainly released by cars and other vehicles. It has no color or smell.
Nitrogen oxides are emitted from vehicles, like cars and trucks. During rush hour periods, a lot more is released in the air. Nitrogen oxides are also emitted from power stations. These gases also make acid rain.
Hydrocarbons are produced when petrol is not fully burnt. They are one of the causes of modern-day smog.
Particulates are very small particles, like soot, dust and fumes that are released in the air. They are caused by vehicles, factories and smoke from homes burning coal for heating.
Gases from factories:
Nitrogen Oxides (see above)
Sulfur dioxide has no color. Most of it is released by power stations. It causes acid rain when mixing with water in the air.
Rain is very important for life. All living things need water to live, even people. Rain brings us the water we need. But in many places in the world even where you live, rain has become a menace. Because of pollution in the air, acid gases from factories, cars and homes, the rain is becoming dangerous for the life of every living creature. This rain is known as 'acid rain'.
WHAT IS ACID RAIN?
Acid gases are produced when fossil fuels like coal and oil are burned in power stations, factories and in our own homes. Most of these acid gases are blown into the sky, and when they mix with the clouds it can cause rain - or snow, sleet, fog, mist or hail - to become more acidic.
The opposites of acid are alkalis; for example, toothpaste and baking powder are both alkalis. Strong alkalis can also be dangerous, such as ammonia and bleach.
Lemon juice, vinegar and cola are all acidic. Rain is naturally acidic, but acid gases make it even more acidic, sometimes as acid as lemon!
Nature can also produce acid gases, such as volcanoes. When they erupt, the smoke that comes out of the crater is also full of acid gases.
Air pollution can be carried over long distances. When acid gases are released, they go high up in the sky, and then they are pushed by strong winds towards other countries.
The acid rain in Sweden is caused by air pollution in Britain and other countries of Europe. The pollution produced in Britain ends up mostly in Scandinavia - countries in northern Europe including Sweden, Norway and Denmark.
When rain is acidic, it affects what it falls on: trees, lakes, buildings and farmland. Sometimes rain is not very acidic and does not cause a lot of problems, but when it is acidic, it can be very harmful to the environment.
TREES AND PLANTS
Acid rain can have terrible effects on a forest. The acid takes away important minerals from the leaves and the soil.
Minerals are like vitamins for trees and plants. Without them, trees and plants cannot grow properly. They lose their leaves and become very weak. They are no longer strong enough to fight against illnesses and frost. They become very ill and can even die.
Some soils are alkaline; when acid rain falls on them the acid becomes neutral. Plants and trees living on these soils are not in any big danger.
LAKES AND WATER LIFE
Acid rain has a terrible effect on water life. Even if the acid rain does not fall straight into the lake, for example, it may enter from rivers and streams. Some of the life in the lake such as fish and plants may end up dying, because they cannot survive in acidic lakes.
Thousands of lakes in Scandinavia have no more life in them. They have received so much acid rain for so many years, because of the winds pushing the acid gases that nothing can survive.
You can recognize a lake dead from acid rain by its clean and crystal clear water. But they look clean because there is very little living in them anymore. Tiny plants and animals are mostly unable to survive..
Particulates - very small particles of debris found in some of the air pollution - are one of the main causes of health problems. In towns and cities, these are released mainly by diesel engines from cars and trucks.
When we breathe in air pollution, these very fine particulates can easily enter our body, where they can cause breathing problems, and over time even cause cancer.
Water we drink from taps can be contaminated by acid rain, which can damage the brain..
Acid rain can also ruin buildings because the acid eats into metal and stone. It also damages stained glass and plastics. Some types of building materials are softer than others, and it is the softer ones which are most affected by acid rain. Sandstone and limestone are examples of stone which are fairly soft and are damaged easily. Granite is an example of a harder stone that can resist the effects of acid rain.
In many places in the world, ancient and famous buildings and monuments are affected by acid rain. For example, the Statue of Liberty in New York, USA, has had to be restored because of acid rain damage. Buildings are naturally eroded by rain, wind, frost and the sun, but when acidic gases are present, it speeds up the erosion.
More particulate matter in the air will be found in the mall area than from the street, backyard and park.
Materials and Equipment:
- Hole Punch
- Magnifying Glasses
View the rest of Air Quality