Table 4. Relative biological effectiveness for neutrons relative to cobalt-60 gamma rays for micronuclei and nucleoplasmic bridges.
| Dose (in Gy) | Induceda micronuclei/1000 binucleated cells | RBEb | Induceda bridges/1000 binucleated cells | RBEb | ||
| Cobalt-60 gamma rays | Neutrons | Cobalt-60 gamma rays | Neutrons | |||
| GM15510 cells | ||||||
| 0 | 0.0 | 0c | 0.0 | 0c | ||
| 0.5 | 121.0 | 255.0 | 2.1 | 2.0 | 40.0 | 20.0 |
| 1.0 | 247.0 | 551.4 | 2.2 | 13.0 | 66.9 | 5.1 |
| 2.0 | 381.0 | 718.8 | 1.9 | 49.0 | 99.7 | 2.0 |
| GM15036 cells | ||||||
| 0 | 0.0 | 0c | 0.0 | 0c | ||
| 0.5 | 124.0 | 173.0 | 1.4 | 32.0 | 32.8 | 1.0 |
| 1.0 | 192.0 | 427.9 | 2.2 | 33.0 | 112.0 | 3.4 |
| 2.0 | 282.0 | 599.3 | 2.1 | 38.0 | 113.3 | 3.0 |
| mean +/− S.E. both cell lines | 2.0±0.13 | 5.8±2.9 | ||||
a
The number of micronuclei or bridges per 1000 binucleated cells after subtracting the baseline (0 dose) values, which were 15.0 and 45.0 for micronuclei and 12.0 and 5.0 for bridges for cobalt-60 gamma for GM15510 and GM15036 cells, respectively. For neutrons the baseline values were 28.0 and 29.1 for micronuclei and 2.0 and 11.6 for bridges for GM15510 and GM15036 cells, respectively.
b
Relative biological effectiveness: neutrons/cobalt-60 gamma rays.
c
Combined values of the controls (pre-radiation, post-radiation and transportation control).