It was 'not sensible' for motorists who drive almost exclusively in towns and cities to buy diesel cars because of air pollution concerns; ?

The pollution concerns don't seem to be dampening people's enthusiasm for gathering around open flames, according to fireplace designers.

Gasoline models have traditionally been two-stroke engines, but four-stroke engines were recently introduced to partially address air pollution concerns.

This led to serious pollution concerns that persist up to the present time.

Leaf blowers are usually powered by two-stroke engine or an electric motor, but four-stroke engines were recently introduced to partially address air pollution concerns.