This is approximately what it looked like near my area in mid July for a few days.

https://commons.wikimedia.org/wiki/File:Wildfire_smoke_Wyand...

It just looks like fog, but it is smoke, and the sky has an unusual orange color. Smells and tastes like you are standing in the path of a campfire, but you can't move out of the way. It irritates your eyes and throat if you spend more than 20 mins out there. You can go inside, but if the building you are in is leaky, it will smell like smoke inside there too.

The actual fire was hundreds of miles away. You can try driving in any direction for hours and not be clear of the smoke. Still, compared to other areas, this is barely worth complaining about.

Anywhere in the US west of Texas and most of Canada.

Allergens are likely considered "infectious particles" for that particular sentence.

>Where do people live that they need to remove such things

SF Bay Area during the summer fires of a few years ago

I use mine just to purify air for my precious LTO tape drive. My baby doesnt like dust

Almost anywhere now in North America or Europe during the summer.

Most of the world, unfortunately. Just look at an air quality map.

As an allergy enjoyer there is no air too pure.

My allergies became generally better at all hours just from sleeping in super cleaned air.

Why? Reducing baseline inflammation perhapse? Maybe decreased inflammation during sleep helps too, improved breathing? idk. Whatever it is this organism seems to prefer it.

Even when exposed to allergens during the day the run up to sneezing is much slower or doesn't happen.