If you come in from moist environment and just leave the lenses lying around, it will take days before the moisture inside the lens drops to ambient levels. You might zoom the lens back and forth several times in a dry room before putting them away, to replace some of the air inside.

Mushrooms in the Lens (http://kotisivu.dnainternet.fi/lauro/fungus.htm)

Fungi in Photographic Lens (http://www.chem.helsinki.fi/%7Etoomas/photo/fungus/)

Dust Mites and Their Relation to Photography (http://www.chem.helsinki.fi/%7Etoomas/photo/dustmite/)

eer..what to do with a prime lens? :) just kidding, cant resist.:)

Thanks for for the heads-up on fungus bro. need to be vigilant with these creeps.

Nice links there Willy! :) Very informative...