An Attempt for Evaluation of the Alveolar Dust Deposition on the Base of the Particle Size Distributions of Lung Dusts.
NIOSH 1990 Nov:933-937
The particle size distributions of mine dusts and dusts recovered from the lungs of workers employed in underground mines (lung dusts) were determined. Mass particle size distributions of 24 dust samples obtained from a polymetal ore mine and 23 samples obtained from two copper mines were determined using the Joyce-Loebl disc centrifuge (Joyce method) and Coulter Counter (CC) techniques. The mass particle size distributions of dusts recovered at autopsy from the lungs of 43 miners who had been employed at the polymetal mine and 16 who had worked at the two copper mines were also determined. The amounts of the dusts deposited and retained in the alveoli (alveolar retention) were determined from the data. The mass median aerodynamic diameters (MMADs) of the three mine dusts were in the range 3 to 5 microns when analyzed by either technique. The mean geometric standard deviations of the MMADs were 4.4 to 5.3 microns for the Joyce analysis and 2.2 to 2.3 microns for the CC analysis. The mean MMADs of the particle size distributions of the lung dusts ranged from 1.9 to 2.6 microns. The mean geometric standard deviations ranged from 3.3 to 3.6 and from 1.6 to 1.8 when analyzed by the Joyce and CC techniques, respectively. Maximum alveolar retention of the dusts occurred for particles having diameters of 1.2 to 4.2 microns. The maximum alveolar retention predicted by theoretical curves of Yu and the International Commission on Radiological Protection occurred for 1.6 to 3.2 and 3.2 to 6.5 microns size particles, respectively. The authors conclude that alveolar retention of inhaled dusts determined from particle size distributions of lung dust is different from that of monodispersed aerosols. The polydispersity of dusts has a significant influence on their alveolar retention.
Dust-analysis; Statistical-analysis; Mathematical-models; Industrial-hygiene; Lung-burden; Respirable-dust; Mine-workers; Occupational-exposure;
Proceedings of the VIIth International Pneumoconioses Conference