"The holes have a diameter smaller than 100 nanometers, or less than a thousandth of the width of a strand of human hair." Air is full of stuff besides gases.

"The holes have a diameter smaller than 100 nanometers, or less than a thousandth of the width of a strand of human hair." Air is full of stuff besides gases. Stuff that can plug holes. Was this tested in a clean-lab? Near a highway? In a restaurant kitchen? During pollen season? So ... how often do I have to wash these thousands of surfaces?