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Prevention

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The best prevention for radiation sickness is to minimize the dose suffered by the human, or to reduce the dose rate. The primary methods of prevention include reducing the time one is exposed, increasing the distance from the source of radiation, and using protective shielding.

Time

The longer that humans are subjected to radiation the larger the dose will be.^[1]

${\displaystyle Dose\propto t}$

Distance

The farther away a person is from a radiation source, the less the exposure. By doubling the distance, exposure is reduced by a factor of four. By halving the distance, exposure is increased by a factor of four.

${\displaystyle Dose\propto {\frac {1}{r^{2}}}}$

Shielding

By placing a layer of material which absorbs radiation between the source and a human, the dose and the dose rate can be reduced. Any material will provide some amount of shielding, but the most commonly used materials are steel, concrete, lead and soil.

in many urban areas.

The specific type of shielding required to absorb radiation depends on its type:

• Alpha particles can be shielded with thin materials, such as a piece of paper or the outer layers of human skin. However, there is still a risk of exposure from inhaled or injested particles.^[3]
• Beta particles can be shielded by heavy clothing. Some beta particles can penetrate and burn the skin.^[3]
• Gamma rays (emitted from nuclear fallout, and also used to sterilize medical equipment and food) require thick, dense shielding such as lead. The higher the energy of the gamma radiation, the thicker the lead must be.^[3]

Reduction of incorporation into the human body

Fractionation of dose

Fractionated doses, or doses spread out over time, can affect radiation poisoning and survivability.^[citation needed] During the Goiânia accident (where residents of Goiânia, Brazil accidently opened an abandoned canister of radioactive materials), the effects of radiation poisoning varied greatly according to exposure over time.^{[citation needed]}

Devair Alves Ferreira, a junk yard owner who purchased the radioactive material to make a ring for his wife, was exposed to a short-term large dose of radiation (7.0 Gy) and lived. His wife, however, received a constant dose of 5.7 Gy over a long period of time and died as a result. The most likely explanation is that his dose was fractionated into many smaller doses which were absorbed over a length of time, while his wife stayed in the house more and was subjected to continuous irradiation without a break.^{[citation needed]} This would give her body less time to repair some of the damage done by the radiation. Similarly, some of the people who worked in the basement of the Chernobyl Nuclear Power Plant received doses of 10 Gy, but in small fractions, so the acute effects were avoided.^{[citation needed]}

It has been found in

are constantly being regenerated in a healthy human) cause death.

In the graph below, dose/survival curves for a

group of cells have been drawn, with and without a rest time for the cells to recover. Other than the recovery time partway through the irradiation, the cells would have been treated identically.

Notes