Air quality

Overview

Click on the links above for teaching schemes, activities and web links and other resources related to this topic.

Timing
In the first year of the course teachers spent anything from 2 to 8 hours of class time on this topic. Depending on the group, it seems that 4- 6 hours seems about right in total.

The sub-topics below suggest a route through the context, science ideas and ideas about science. This is not a division into sub-topics of equal extent and they do not all need the same amount of time.

A suggested route through the topic

1 Setting the scene

Start the topic with one or more of the following:

• Ask students what they already know about air pollution.
• Ask students to reflect on the signs of symptoms of air pollution which they notice on their way to and from school.
• Display a few recent newspapers or magazine articles/headlines related to the topic.
• Ask students to look at the sky on a bright sunny day in many parts of the UK there are visible signs of photochemical smog near the horizon.
• Use a short video as a starter (e.g. start of Sun, cities and smog from the OU)
• Introduce and explain the main types of pollutants.

2 Types of pollution

• Opening questions for discussion:
  What are the key pollutants which need to be monitored?
  How are cars now designed to limit air pollution?
• Use a web site, such as National Atmospheric Emissions Inventory to look at patterns of air pollution in different areas. URL in Web links section of this Topic.
• Ask students to produce a summary table in their notes about the main pollutants (What is it? Where does it come from? What harm does it do?). Possible sources of information: web sites, the textbook, some of the ARIC fact sheets from Manchester Metropolitan University: See Web links section of this Topic for URL.
• Alternatively ask each group to tackle one pollutant expect them to produce an OHT summarising their findings and then to make a short presentation to the class. Give everyone copies of all the OHTs at the end.
• Matching exercise (see worksheet): to cover pollutants from a car exhaust.

3 The chemical changes

• Demonstrate the classic burning candle experiment collecting and condensing water vapour and detecting carbon dioxide also noting soot.
• Use a set of molecular models to model the changes to simple hydrocarbon and oxygen molecules during burning.
• Show students a carbon monoxide detector ask them what it is for and why it is needed.
• Invite students more confident in their knowledge of chemistry to explain to the rest of the class the chemistry of burning and pollution.
• Teacher or students use an enlarged copy of figure 11.2 on page144 of the textbook to summarise the key ideas about chemical change.
• Discuss the strange case of NOx how do oxides of nitrogen get into car exhausts given that nitrogen is often thought to be pretty inert?

4 Monitoring and measurement

• Find out about local monitoring stations with the help of web sites: Such as Department for Environment, Food and Rural Affairs. See Web link section of this Topic for URL.
• Use the web sites or teletext to study current pollution levels and forecasts.
• Let a drop of perfume evaporate in the room and then estimate the concentration of perfume in the air as a way of introducing concentration units.
• Explore the meaning of concentration units with the help of the table and questions on page 145 of the textbook.
• Explore ideas of measurement and errors. Use the questions in the book on page 145 to start discussion.
• Look at statements about degrees of certainty or uncertainty in measurements on web sites such as National Atmospheric Inventory. See Web links section of this Topic for URL.
• Give each group a thermometer and ask them each to measure a specified temperature and report their result with a comment on precision and accuracy. Compare the reports of different groups and discuss.

5 Air quality and respiratory disease

• Show and discuss a video: e.g. London smogs or Los Angeles smogs.
• Explore health effects of the different pollutants with the help of the ARIC fact sheets
• Plot daily rate of absence in your school or college against levels of different pollutants over a period of time to see if there is any correlation.
• Discuss the graph on pages 149-150 in the textbook. Take the opportunity to discuss the difference between correlation and cause and effect.

6 What can be done about it? Will you help?

• Discuss: Why do motorists put 'green' fuel in their car? Is it cheaper and if so why?
• Cover technical and regulatory tactics for cutting pollution with the help of the book and ARIC fact sheets. See web links section of this Topic for URL. Read and interpret the text (web or book) and then answer questions.
• Draw up a timeline showing key events in the history of pollution control.
• Discuss lifestyle issues e.g. 'Are you prepared to use your car less to cut air pollution?' (Note links to the energy topic)
• Set up a role play or debate with interest groups such as: Dept of Environment, Industry, Motorist organisation, Health worker, Local government, Environmental pressure group. Debate an issues such as: 'Should there be congestion charging in London?', 'Should the local motorway be widened?', 'Should this new by-pass be built?', 'Should petrol should be more expensive?'

Summary
A poster session. Each group tackles a part of the whole topic, producing and presenting a 'poster paper' to summarise the key ideas.