US EPA

3098189 

Journal Article 

Asbestos Dust Deposition and Retention in Rats 

Wagner, JC; Skidmore, JW 

1965 

Yes 

Annals of the New York Academy of Sciences
ISSN: 0077-8923
EISSN: 1749-6632 

NIOSH/00191660 

132 

1 

77-86 

English 

5219586 

10.1111/j.1749-6632.1965.tb41091.x 

A series of dusting experiments were conducted in which the deposition and retention of asbestos (1332214) dust in female Wistar-rats were observed. First it was necessary to develop an experimental method by which equal amounts of any asbestos dust could be deposited in the lungs of rats by an inhalation method. It was also necessary to ascertain whether the various types of asbestos were retained in the lungs to the same extent and had a similar histological distribution. The airborne dust clouds were generated by redispersing ground asbestos. Gravimetric dust sampling was used to measure the concentrations of the airborne dust clouds. The rats were exposed for 7.5 hours a day on 5 days a week over a period of 6 weeks. The dusts tended to accumulate in the alveoli arising directly from the respiratory bronchioles. The weights of the asbestos dusts found in the lungs at the end of the exposure differed considerably, but the subsequently determined elimination rates indicated that the weights of dust deposited were in constant ratio with the weights of dust collected by the size selective sampler. Allowance must be made for the reduced efficiency of the upper respiratory tract in preventing the penetration of the compact dust particles to the alveolar regions in order to deposit an equal amount of a nonfibrous dust. The elimination rate of Rhodesian chrysotile (12001295) was three times greater than that of amosite (12172735) and crocidolite (12001284). 

Minerals; Index Medicus; Animals; In Vitro Techniques; Pulmonary Alveoli -- pathology; Asbestosis -- pathology; Lung -- pathology