A particle of size 5 to 10 micron all EXCEPT
Particles larger than 30 to 35 micron are not inhaled. Particles of size 5 to 10 micron most are stuck in upper airways but some are passed down to conducting airways.
5 to 10 microns sized particles have the momentum so they get stuck to mucous membrane due to curved airways. These impact posterior nasopharynx and adenoid and tonsils.