Total Dose Received - DOE-HDBK-1109-97

DOE-HDBK-1109-97

Radiological Safety Training for Radiation-Producing (X-Ray) Devices

Student's Guide

ii. Total Dose Received.

The higher the total amount of radiation received, the greater the biological effects. The

effects of a whole body dose of less than 25 rem are generally not clinically observable.

For doses of 25-100 rem there are generally no symptoms, but a few persons may exhibit

mild prodromal symptoms, such as nausea and anorexia. Bone-marrow damage may be

noted, and a decrease in red and white blood-cell counts and platelet count should be

discernable. 100-300 rem may result in mild to severe nausea, malaise, anorexia, and

infection. Hematologic damage will be more severe. Recovery is probable, though not

assured.

Although effects of lower doses have not been observed directly, it is conservatively

assumed that the higher the total dose, the greater the risk of contracting fatal cancer

without consideration of a threshold for effects. This conservative assumption is

sometimes called the "linear no threshold" relationship of health effects to dose.

iii. Energy of the Radiation.

The energy of X-rays can vary from less than 1 keV up to more than 10 MeV. The higher

the energy of the X-ray, the more penetrating it will be into body tissue.

Lower energy X-rays are largely absorbed in the skin. They can cause a significant skin

dose but may contribute little dose to the whole body (depending on energy).

iv. Area of the Body Exposed.

Just as a burn to a large portion of the body is more damaging than a burn confined to a

smaller area, so also is a radiation dose to the whole body more damaging than a dose to

only a small area. In addition, the larger the area, the more difficult it is for the body to

repair the damage.