| microwave radiation | 2.63 | High levels of microwave radiation are known to be dangerous. | ||
| background radiation | 2.30 | In some parts of the world, background radiation is very high. | ||
| gamma radiation | 1.91 | Gamma radiation has its drawbacks. | ||
| space radiation | 0.53 | Space radiation could cause cancer. | ||
| beta radiation | 0.46 | As a result, some have turned to beta radiation. | ||
| measure radiation | 0.39 | Another instrument measures radiation and how that might endanger humans if they ever explore Mars. |