You could buy the Netatmo healthy home coach if you want more plug and play CO2-sensors.
PM2.5/PM10-sensors reacts to particles in the air, like dust, smoke, pollen and so on.
VOC-sensors also reacts to human breathe but also to general “bad smell”, paint and so on. And sometimes it’s a bit to hard why the value is increased. Often the value is calculated to some index instead of ppm where low value is the best air quality the sensor has measured and a high value is the worst. The sensors often self calibrate so it’s not possible to compare those values between different homes but they are good to measure the change in air quality in a specific location.
