dust veil in a sentence

1. Often, a sickly cloud of exhaust fumes and dust veils the gorgeous mountains.
2. Others, including Hubert Lamb, who created a Dust Veil Index, thought volcanoes were more responsible for global-scale aerosol.
3. Victor Clube and Bill Napier support a controversial theory that a short period comet in an Earth crossing orbit doesn't need to impact to be hazardous, as it could disintegrate and cause a dust veil with possibilities of a " nuclear winter " scenario with long term global cooling lasting for thousands of years ( which they consider to be similar in probability to a 1 km impact ).
4. It's difficult to find dust veil in a sentence.