Exhaust pollution increases sharply on a winter's day.

This time period led to about 25 per cent of the total exposure to exhaust pollution.

Diesels aren't ideal in town: lots of short runs can clog their exhaust pollution filters.

By the late 1980s, automobile exhaust pollution had been noticeably improved, but more stringent regulations forced car manufacturers to adopt the use of electronically controlled fuel injection and hypereutectic pistons.