Hi JJ:

Your pulmonologist is partly right -while it's true that the particle size of most fiberglass is too large to stay airborne and reach the terminal branches of the lung, flame-attenuated fiberglass particles are, like asbestos, fully respirable and can. Unlike asbestos, the body can process some glass fibers which offers a bit of protection but the best bet is not to breath the stuff in the first place and never ever smoke.

Best,

Ray Warshaw