[rahimnathwani]

Filtering air at home has a big impact, because:

- You have a lot of control over your home's internal environment

- You probably spend 1/3 to 1/2 your time at home

It's also challenging:

- All windows and doors must be sealed from draughts to minimise pollution coming in

- Filter machines must be regularly maintained, and filters replaced

- Windows must be opened for short periods (e.g. 20 mins) a couple of times per day, to let bad gases out, and let oxygen in

Sure, you can wear a mask in other environments, but you probably take the mask for many functions (talking with people, eating).