D. Smog

Smog looks like a mixture of smoke and fog, which is why it's called smog. It is made up of particulates, which are formed by a complex reaction between various oxides of nitrogen and a wide range of hydrocarbons, which is triggered by sunlight. This means that smog tends to form in urban areas where there are lots of cars, and especially where the air is stagnant, so the smog isn't dispersed naturally. In Britain, road transport is responsible for over a third of our hydrocarbon emissions, and half the nitrogen dioxide emissions.

Smog is mainly caused by cars, so the best way to reduce smog is not to use cars. However, this is not a very practical solution. More realistically, if you drive a car:

• Avoid using your car when pollution levels are high if it doesn't have a catalytic converter
• Don't use your car at all for short journeys (less than 1.5 miles)
• Don't use the choke more than you have to
• If you expect to be stopped in traffic for more than a couple of minutes, switch off your engine
• Try not to fill up with petrol when pollution levels are high

Pollution levels are reported in the weather forecast if they are high. If you don't have a car, try to persuade somebody you know who does to follow these guidelines. Most of them also improve fuel economy, making the car cheaper to run as an added bonus!

Assignment:

Answer the following questions on a separate sheet. You must copy out the question, and neatly put the answer below each question. (8)  Include the title “Smog”.