Poor air quality can lead to a range of health problems, including respiratory and cardiovascular disease, stroke, and lung cancer. Measuring CO2 levels is crucial as it essentially displaces oxygen in the air, leading to drowsiness, headaches and other harmful effects. Dust and other particles less than 10 micrometers in diameter can get deep into your lungs and some may even get into your bloodstream. Of these, particlesess than 2.5 micrometers in diameter, pose the greatest risk to health.