Table 2 Characteristics of 13-week subchronic exposure
From: Persistent effects of Libby amphibole and amosite asbestos following subchronic inhalation in rats
| Â | Air control | AM | LA | LA | LA |
|---|---|---|---|---|---|
Target mass concentration (mg/m3) | 0.00 | 3.30 | 1.00 | 3.30 | 10.00 |
Actual mass concentration (mg/m3) | 0.00 ± 0.16 | 3.32 ± 1.48 | 1.01 ± 0.45 | 3.34 ± 0.83 | 10.04 ± 2.04 |
APS: Count median aerodynamic diameter (μm) | 1.41 ± 0.98 | 0.93 ± 0.04 | 1.05 ± 0.06 | 1.02 ± 0.03 | 1.13 ± 0.05 |
APS: σg | 2.01 ± 0.58 | 1.40 ± 0.08 | 1.51 ± 0.03 | 1.46 ± 0.02 | 1.52 ± 0.04 |
APS: Particles/cc | 1 ± 3 | 404 ± 132 | 43 ± 23 | 171 ± 56 | 280 ± 96 |
SEM: All structures/cc | - | 3101 ± 598 | 1158 ± 217 | 3728 ± 772 | 6718 ± 958 |
SEM: Total structures counted (n) | - | 3218 | 2557 | 4517 | 2674 |
SEM: All structure lengths, L (μm) |  |  |  |  |  |
 Mean | - | 1.9 ± 0.1 | 2.6 ± 0.4 | 3.3 ± 0.4 | 3.7 ± 0.4 |
 Median | 1.0 ± 0.1 | 1.4 ± 0.4 | 2.2 ± 0.4 | 2.5 ± 0.4 | |
 Maximum | 21.0 ± 7.1 | 22.0 ± 6.0 | 25.3 ± 5.0 | 27.5 ± 8.4 | |
SEM: All structure diameters, D (μm) |  |  |  |  |  |
 Mean | - | 0.33 ± 0.01 | 0.38 ± 0.03 | 0.43 ± 0.02 | 0.44 ± 0.03 |
 Median | 0.29 ± 0.01 | 0.32 ± 0.02 | 0.36 ± 0.02 | 0.37 ± 0.03 | |
 Maximum | 1.38 ± 0.85 | 2.14 ± 0.78 | 2.29 ± 0.52 | 2.56 ± 1.29 | |
SEM: All structure aspect ratios (L/D) | Â | Â | Â | Â | Â |
 Mean | - | 5.8 ± 0.5 | 7.0 ± 0.9 | 8.7 ± 0.9 | 9.5 ± 0.8 |
 Median | 3.1 ± 0.3 | 3.8 ± 0.7 | 5.6 ± 0.9 | 6.2 ± 0.7 | |
 Maximum | 60.7 ± 16.4 | 69.5 ± 36.6 | 86.8 ± 41.2 | 85.5 ± 42.4 | |
SEM: WHO fibers/cc (L/D ≥3; L ≥5 μm) | - | 230 ± 56 | 159 ± 63 | 693 ± 199 | 1522 ± 304 |
SEM: Total WHO fibers counted (n) | Â | 237 | 349 | 838 | 601 |
Proportion of structures which are WHO fibers (%) | - | 7.4 | 13.6 | 18.6 | 22.5 |
SEM: WHO fiber L (μm) |  |  |  |  |  |
 Mean | - | 8.9 ± 0.9 | 9.0 ± 0.8 | 9.0 ± 0.6 | 9.3 ± 0.7 |
 Median | 7.3 ± 0.9 | 7.6 ± 0.7 | 7.6 ± 0.4 | 7.7 ± 0.6 | |
SEM: WHO fiber D (μm) |  |  |  |  |  |
 Mean | - | 0.41 ± 0.04 | 0.51 ± 0.09 | 0.49 ± 0.03 | 0.52 ± 0.05 |
 Median | 0.37 ± 0.04 | 0.44 ± 0.08 | 0.42 ± 0.03 | 0.45 ± 0.04 | |
 Maximum | 0.80 ± 0.25 | 1.46 ± 0.72 | 1.66 ± 0.48 | 1.47 ± 0.39 | |
SEM: WHO fiber aspect ratios (L/D) | Â | Â | Â | Â | Â |
 Mean | - | 24.8 ± 3.7 | 22.1 ± 2.8 | 22.5 ± 2.4 | 22.3 ± 2.1 |
 Median | 21.5 ± 3.9 | 18.6 ± 2.6 | 18.7 ± 1.6 | 17.7 ± 1.9 | |
SEM: Fibers, L ≥20 μm/cc (L/D ≥3) | - | 7 ± 10 | 5 ± 6 | 26 ± 18 | 75 ± 52 |
Proportion of WHO fibers with L ≥20 μm (%) | - | 3.0 | 3.2 | 3.8 | 4.8 |