Experimental Pneumoconiosis of Sandblasting Substitutes

摘要

A study was conducted to evaluate the pulmonary fibrogenic potential of Stanblast. This substance is a sand substitute extensively used in the State of Louisiana. The study was conducted using both normal and silicotic rats. Analysis indicated that Stanblast was a complex silicate with trace amounts of several elements. Stanblast granules were milled in a ball mill to produced dust for animal exposures. Male rats were exposed by inhalation in a horizontal laminar flow whole body exposure chamber to 10.8 milligrams of the Stanblast dust/cubic meter, 6 hours a day, 5 days a week for 1 year. Rats were killed 6 to 24 months after the start of exposure, and lungs were examined. Histologic examinations of the exposed lungs revealed the presence of microgranulomas throughout the lung fields, suggesting the release of certain cellular modifying agents. The absence of any obvious collagen deposition within the structures of the surrounding interstitium indicated a lack of fibrogenic potential for Stanblast under the conditions of the experiment. The lack of significant difference in hydroxyproline content of the lungs of exposed and control rats corroborated the histologic conclusions.