Magnetometric evaluation for toxicity of titanium dioxide to alveolar macrophages

Asbestos, a family of fibrous silicates, causes various pulmonary diseases including lung cancer. Therefore, various substitutes for asbestos are used in work places, a en though their toxicity has not been completely investigated. The present report was designed to clarify the toxicity of titanium dioxide whiskers on the alveolar macrophages in hamsters using magnetometry and enzyme release assays. Alveolar macrophages were obtained from hamsters by tracheobronchial lavage, adhered to a disk in the bottom of wells, and were exposed to ferrosoferric oxide and titanium dioxide whiskers. Ferrosoferric oxide particles were magnetized externally and remanent magnetic field was measured. Dose-dependent delay of relaxation was observed in the cells exposed to titanium dioxide whiskers. This finding may indicate the toxicity of titanium dioxide whiskers to alveolar macrophages.