Whole generation of kids going to have shortened lives and quality of life.
BTW this exists also in the USA, legally allowed toxic zones in populated areas
Much as I love living out West, this might be the straw that breaks the camel's back.
At air pollution levels that high more filters for use in a home won't move enough air through the filter fast enough to matter and the filters will quickly clog and stop working. You can see examples of this in reports of US and Australian wild fires over the last few years.
For things like schools and offices you need a really large and sophisticated HVAC system to deal with that amount of shit in the air. I'd be surprised if any buildings in Dehli have systems like that.
And as for the HVAC systems, the luxury hotels definitely have them going. When I was staying there night time AQI would get up to 600, but if you were at a nice hotel it wasn't bad at all. When we stayed at an airbnb without a filtration system it was really difficult to sleep, I'd tie a kufiya around my face.
That doesn't mean they work. Cars just aren't well sealed in general and you need to move a lot of air through a filter to clear the space faster than pollution is coming in. You might make a small dent but it isn't going to be great. The second you open the door or turn on the A/C you've lost the game.
I'm sure luxury hotels have good HVAC, but an AQI of 600 is just not what any traditional HVAC system is designed for. Now there have been advances and a bunch of stuff was specifically developed for the Beijing olympics, but that's a much lower level of pollution. Even there, high end hotels are running two HVAC systems. It's clearly not impossible, but merely being wealthy isn't going to save you from that level of pollution, it's just going to be less bad.
And wealth definitely isn't going to fully save you from it -- the NY Times did a comparative piece on it a couple years ago: https://www.nytimes.com/interactive/2020/12/17/world/asia/in...