What Makes Fresh Air Fresh?

The video explores the differences between outdoor and indoor air quality, highlighting that indoor air can be more polluted due to factors like pet dander, mold, and organic compounds from furniture. It discusses various methods to freshen indoor air, such as air fresheners and air ionizers, noting their limitations and potential health risks, particularly the production of ozone by ionizers. The video concludes with safer alternatives like using indoor plants or improving ventilation by opening windows.

What is the function of air ionizers as described in the text?

What alternative methods are suggested for improving indoor air quality?