@ingrid1947 Yes they can be - there are numerous articles about it.
BUT - do you need to? As far as I know, even as cautious as the staff at NJH (National Jewish Health) they have never recommended this measure in any of their seminars.
It might be a good question to ask at the upcoming patient conference on September 19th (in person & online). You can register here: https://www.nationaljewish.org/2026-ntm-bronchiectasis-patient-and-family-course-hybrid-event