Acute radiation sickness in Mars settlements may result from prolonged exposure to solar radiation or accidental exposure to radioactive materials.
- Settlers on the surface of Mars, with no protection (only a light weight space suit protecting them from the tenuous and cold Mars atmosphere) may receive leathal doses of solar radiation during solar storms.
- Astronauts in Mars orbit will also be unprotected (unlike Earth orbit, where low orbits are protected by the Earth's magnetic field), so some spacewalk tasks should be carried out by robots whenever possible and sufficient protection must be provided when a solar storm is imminent.
Accidental exposure to radioactive material
- Should nuclear power be required by an expanding settlement, accidental exposure to radioactive material may result in injury or death. Long-term health problems (such as cancer) may result from being in close proximity to such materials.