Travelling on a plane for instance.
Not sure myself, they have Hepa filters on planes, i think the airport is riskier.
The last category strikes me as risky because you are eating and drinking and ingesting into your system. Take a bar, you have close proximity in an enclosed place, a lot of aerosol, no face coverings, impaired judgement and probably drinking from a glass about 20 - 50 other people have been in the last 24 hours.

