1.   A model system relates energy consumption to emissions of sulphur and nitrogen oxide emissions.

2.   Nitrogen oxide emissions from vehicles are rising every year because of the huge growth in the number of cars.

3.   Nitrogen oxide Forty percent of nitrogen oxide emissions in Britain come from vehicles.

4.   Both countries would also limit nitrogen oxide emissions through stricter controls on motor vehicles.

5.   Both countries will also limit nitrogen oxide emissions through stricter controls on motor vehicles.

6.   The fuel, known as rape methyl ester, emits no sulphur dioxide, halves deposits of particulates and reduces carbon monoxide and nitrogen oxide emissions.

7.   Carmakers have taken significant steps to reduce nitrogen oxide emissions, the EPA said.

8.   Common sources of the particles are sulfur and nitrogen oxide emissions from smokestacks and tail pipes.

9.   Ground-level ozone is formed by a combination of volatile organic compounds and nitrogen oxide emissions.