Pathological study of acute pulmonary toxicity induced by intratracheally instilled Asian sand dust (kosa).

The objective of this study was to investigate acute lung toxicity caused by Asian sand dust. Simulated Asian sand dust collected from the Tennger desert in China (CJ-2 particles) and Asian sand dust collected from the atmosphere in Japan (Tottori particles) were used. Saline suspensions of 50, 200, 800, and 3,000 µg Asian sand dust were intratracheally instilled to ICR mice. Localized accumulation of the dust particles was observed in the bronchioles and the alveoli of the lung tissues; acute inflammatory changes characterized by infiltration of macrophages and neutrophils were observed around the particles. Degenerated alveolar walls and bronchial epithelial cells, as well as a weakened positive immunolabeling for laminin, were observed to be associated with particle attachment. Positive immunolabelings for interleukin-6, tumor necrosis factor-α inducible nitric oxide synthase, and dimeric copper- and zinc-containing superoxide dismutase were observed mainly in the inflammatory cells in the lesions; these findings were not observed in the controls or in areas lacking lesions. These results suggest that Asian sand dust particles caused damage to the lung tissue through a direct physical effect. In addition, secondary released cytokines and oxidative stress generated in the lesion may be involved in the development of the acute lung toxicity.