@luckytran I would like to know how this relates to long-term health. In the 90s it was recommended to avoid peanuts for small children which then caused a whole generation to develop peanut allergies. Or how overly sterile environments raise the risk of asthma later in life.

Sometimes exposure is great, sometimes it isn't. From what I can tell it's not entirely clear whether air filters are a good idea for the development of a child's immune system