Pulmonary deposition and chemical composition of biosoluble vitreous fibers

INTRODUCTION How inhaled fibers may cause cell damage related to tumor formation is presently not exactly known, although there are several hypotheses about it. In vivo studies have provided evidences that the most important parameters to determine the carcinogenicity and the toxicity of fibers are the dimensions, the local doses and the particles’ chemical compositions. Fiber length and alveolar geometry appear to be important limiting factors for the submersion of vitreous fibers into the lungs’ surface lining layer. Fiber dimensions are considered to be important because the macrophages that normally remove particles from the lungs cannot engulf fibers much longer than the macrophage diameter. The chemical composition of fibrous materials plays an important role in fiber-induced toxicity, while fiber biodurability directly correlates with pathogenic potential as it was observed in rodents (Jackel et al, 2005). The main objectives of this study were to determine the deposition pattern of inhaled fibers in the human respiratory system and the concentration of macroand microcomponents.