Fig. 2.

SEM micrographs of sections of embedded human lung epithelial cells (A549) exposed to 10.4 µg Al₂O₃/cm² cell layer and medium without particles (control) for 24 h. The area subjected to EDX analysis is marked with a red rectangle. Heavy elements (e.g., aluminum) appear as light electron dense areas. No aluminum was detected in control cells. All three types of particles were incorporated by the cells and were located in the cell cytoplasm (CP). No particles were detected in the cell nucleus (N)