Sulfur dioxide may be removed from the waste gases by a process called gas scrubbing.
The emission of air pollutants from cars may be reduced by people using their cars less by, for example:
Engineers are developing engines for vehicles that are more efficient. This means that the engine uses less fuel and so produces less air pollution.
A catalytic converter, fitted to the exhaust of a car, changes the pollutants carbon monoxide and nitrogen monoxide into less harmful carbon dioxide and nitrogen.
The use of low-sulfur fuels has reduced the amount of sulfur dioxide in car emissions.