Sure, air quality is relative, but 100 AQI is the point where I start getting headaches. Obviously it can get much worse. I got the air filters on Amazon, whic

Sure, air quality is relative, but 100 AQI is the point where I start getting headaches. Obviously it can get much worse. I got the air filters on Amazon, which can be US centric, but usually you would get them at a home/hardware store. They are made for slotting into a furnace/HVAC set up. For places where that is less common, they may be harder to find.