Geography: Section 1

Air Pollution: Background Information

After completing this section you will be able to:

  • Explain what is meant by air pollution
  • Explain why it is important to study air pollution.
  • Identify the possible sources of air pollution.
  • Describe who monitors air pollution and how air pollution is monitored

Click here to download & print the Activity Sheet for this lesson.

What is Air Pollution?

Air pollution is the introduction of harmful gases and particles, into the atmosphere that makes the air harmful to humans and to the environment. When air pollution occurs it is very difficult to avoid because it can easily spread by the wind and we are always breathing air in.

Use the information in this video to complete Activity One in the Activity Sheet.

What Causes Air Pollution?

There are seven factors that can cause air pollution. These factors can be grouped into physical and human factors. To learn more about the major pollutants that cause air pollution take a look at the interactive element below:

Pollutants

Click the X at the top right of this window to close this window then click the pink spots on the graphic to learn more about that pollutant.

Power

Stop and think for a moment how much gas or electricity you have used since you got up this morning. Did you know that the power we use in our homes, communities and workplaces is generated by burning other fuels? These fuels include coal, gas and oil. When these fuels are burned to generate power they release pollutants, such as sulphur dioxide and other greenhouse gases into our atmosphere.

Agriculture

We have lots of farms that rear cows and sheep for either their meat, milk or for their wool or hide but one thing they produce that we don’t necessarily want is the gas methane. Methane is produced by livestock after they eat and digest grass and this is broken up by bacteria to produce methane which then makes its way into the air when the animal releases wind. Methane is one of the main greenhouse gases which can cause climate change and livestock is the biggest source of methane. As well as this, particulates (PM10) can arise through dust being blown off farmer’s fields.

Weather

Although many contributing factors can be found in any one place it is important to note that the weather can affect air pollution levels. The wind for example can carry and move pollutants from one area to another and spread them out. On a windy day air pollution levels might be lower than you would expect. Likewise a very calm day may see higher than expected levels as there is no wind to take away the pollutants. The rain can also affect air pollution by washing out pollutants from the air.

Transport

Think of a road close to your school or home. How many vehicles do you think travel along that road each day? Each car, van, bus, lorry and motorbike that travels along that road produces pollutants such as carbon monoxide, particulate matter and nitrogen oxide, which are generated by the burning of diesel or petrol that powers each vehicle. A busy road with a lot of vehicles would see higher levels of air pollution. If you think of all the roads within your town or city, or even within Scotland, it is easy to see how road transport is one of the most significant contributing factors to air pollution.

Towns & Cities

Towns and cities suffer from the highest levels of air pollution. If you think about what you have already learned about waste, power and transport it is no surprise then that air pollution can be so high. Think about the sheer number of cars, buses, factories and homes, all found in one town or city and the volume of pollutants that each one creates.

Natural Sources

Natural sources of pollutants from naturally occurring process or events can also put pollutants into the air. An active volcano can produce smoke, ash, carbon dioxide and sulphur dioxide that all goes up into the air. Forest fires sparked by very hot and dry weather conditions can emit carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone, and particulate matter into the air. All of which contribute to air pollution.

Waste

Every day we throw out bags and bags of rubbish. Some might get recycled, some might be burned to produce energy with the rest sent to landfill where it rots and decomposes in the ground. As it rots it produces methane which as we have already learned is a major greenhouse gas.

Power

Stop and think for a moment how much gas or electricity you have used since you got up this morning. Did you know that the power we use in our homes, communities and workplaces is generated by burning other fuels? These fuels include coal, gas and oil. When these fuels are burned to generate power they release pollutants, such as sulphur dioxide and other greenhouse gases into our atmosphere.

Can you identify what the seven factors are? Click on each one to discover how each of these factors contributes to air pollution and use the information to complete Activity Two in the Activity Sheet.

Monitoring Air Quality in Scotland

Use the information in this video to complete Activity Three in the Activity Sheet.

How We Travel to School Survey

To get you starting to think about the causes of air pollution ¬†your class can use the ‘how we travel to school survey’ to allow your class to see how you affect air quality with the journey you make to school.

You can input the result of one of your travel surveys here: Travel Survey Entry.

The data you input will be automatically converted into graphs for your next lesson. You will also be able to compare your classes’ results with that of other schools and use that information to complete an Activity sheet in the next section of this site.

For more information on the state of Scotland’s Air Quality, check out Scotland’s Environment Website

There is also a Homework Sheet you can download that supports and develops further the ideas from this section.