Table 2.
Summary of stereological results
| Particle size/number concentration | APM surface area density [μm-1] | Number-weighted mean volume of A549 cells [μm3] | Total APM surface area per A549 cell [μm2] |
| Negative control | 0.251 (0.043) | 1016.3 (92.2) | 254.6 (45.9) |
| 1 μm/3 × 107 | 0.247 (0.036) | 1052.2 (69.9) | 259.7 (41.8) |
| 1 μm/6 × 108 | 0.336 (0.048) * | 1468.6 (238.4) * | 492.5 (98.2) * |
| 0.05 μm/3 × 107 | 0.247 (0.040) | 1090.8 (144.5) | 267.3 (43.9) |
| 0.05 μm/6 × 108 | 0.239 (0.055) | 1077.6 (108.9) | 256.2 (57.4) |
| 0.05 μm/4.5 × 1011 | 0.376 (0.061) * | 1211.6 (75.1) | 454.8 (72.2) * |
Note. Data are presented as mean (standard deviation). The asterisk (*) indicates a significant difference versus negative control (p < 0.01). The APM surface area density and total surface area per A549 cell were significantly increased at 1 μm/6 × 108 and 0.05 μm/4.5 × 1011. Only at 1 μm/6 × 108 was the number-weighted mean volume of A549 cells enhanced, probably due to the ingested particles.