A $200 air purifier can make a world of difference: https://www.nytimes.com/wirecutter/reviews/best-air-purifier... (I own a Coway Airmega 200M.)

I bought a Temtop monitor to verify if the "smart mode" (where it only runs if the air quality is low): https://www.amazon.com/gp/product/B07DHXQXGK/

I live in Los Angeles where the air quality isn't that great and in a rented apartment where I have limited choices. The air purifier made a dramatic difference in the first hour I had it and now it keeps the PM2.5 reading down to around 2-4 with minimal cycling.