When the kiddo was born, I went a little crazy with air quality monitors and purifiers. This is LA so that seemed important. And even with the fires, etc., the biggest lesson I've learned is:

Holy crap don't have gas ovens/stoves. And open the windows when cooking with them.

@mttaggart I recently completed a retrofit to replace a gas stove with induction. Next up is replacing the hvac with a heat pump.