immediately after a 20 min nose only exposure to 51cr labeled polystyrene latex microspheres ( 1.4 mmad , geometric standard deviation = 1.3 , 2 micrograms m-3 ) , 23 % of the measured radioactivity was within the trachea-lungs of the exposed rats , 37 % was within the gastrointestinal tract , 10 % was within the defurred head , and 30 % was on the fur .
C0028429
nose
C0018670
head