Radiation sickness

Acute radiation sickness in Mars settlements may result from prolonged exposure to solar radiation or accidental exposure to radioactive materials.

Sources of radiation

Solar radiation

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. People in transit to Mars, or in Mars orbit, would go into a Storm shelter if there is an active solar storm.

Galactic cosmic rays

Galactic cosmic rays (GCR) are a form of damaging radiation that require shielding for protection against long term exposure. GCRs are mostly protons (hydrogen with no electron) or other atomic nuclei. They move at very high velocities, and the fastest ones have much more kinetic energy than even the highest energy photons. They therefore do proportionally more damage than other types of radiation and are difficult to protect against. On Earth, the depth and density of the atmosphere block most cosmic rays. But on Mars the atmosphere is not dense enough and additional protection is required.

See Cosmic radiation for more information.

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.

Symptoms and treatment

Acute radiation syndrome is the result of Ionisation damage from intense radiation

Cancer is a longer term result from radiation exposure

Nerve damage

Cooking of tissue

Genetic damage

Protection

Radiation shielding

Exposition limits are used to define what can be acceptable as far as radiation dosages go. As the body can self repair up to a point, some radiation is acceptable. Rather like sunscreen, that protects against low power radiation from the sun, so sunbathers can stay out longer.