Can you direct me to more detailed information that could help to identify any potential sources of pollutant types detected?

(And also to help determine if additional steps I might take to rectify some persistent source of pollutant have been effective too)?

For example, in my bathroom the HP07 Hot + Cool Purifier is reading poor for PM2.5 and very poor for PM10. The humidity has been sitting in the 50-60% range the entire time it has been operating there. The levels for VOC and NO2 are zero. There isn't a window in there; nor any smoke or candles, and no plants producing pollen. I could guess at perhaps this must be from some mold somewhere - would that register on the PM10 sensor? Bacteria? Also, what else might effect the PM2.5 reading? Dust? Cleaning and cosmetic products? It took a while to register these higher levels and in that time all I did was wash my hands once. Therefore I assume it took a little while for the sensor readings to 'warm up' rather than an actual decrease in air quality occurring.

I just submitted a reply post here that is yet to be reviewed by the moderator but I have a relevant update to add. In my previous reply, I speculated that the sensors on my new HP07 purifier might not register as many particles etc until it had been running for a while (i.e. implying a much longer timeframe than 20 minutes). But I was wrong! I actually found that there was a faulty appliance in the next room that had started emitting smokey-looking fumes and the air quality readings were reflecting as and getting progressively worse.

Dyson, you may have just saved my life!

Thank you for the information.

I am thinking about to purchase the new Dyson purifier Dyson Purifier Big+Quiet Formaldehyde (Satin Dark Blue/Gold).

But on Dyson Australian official website I could not find information about whether this purifier can remove the indoor chemicals in the air result from smoking cigarette/tobacco - in particularly carbon monoxide (CO)? If so, how efficient it removes CO from the air in an indoor place?