FIG. 3.

Histopathology of lung from the SWCNT, AB, or UFCB repeated aspiration study (40 micrograms per mouse, twice a week, for 3 weeks): SWCNTs caused granuloma formation near bronchioles and adjacent alveoli. Fibrosis found within these granulomas extended for a short distance into surrounding septal walls. Arrows indicate agglomerates of SWCNTs within granulomas. In AB-treated animals, multinucleated giant cells were common, but classic granulomas were not observed, and an increase in fibrous tissue (minimal to mild) was observed in several specimens.