Heritable Effects - hdbk110997

DOE-HDBK-1109-97

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

Student's Guide

Workers who become pregnant are encouraged to declare their pregnancy in writing to

their supervisors. The dose limit for the embryo/fetus of a declared pregnant worker is

500 mrem during the term of the pregnancy; 10 CFR 835.206 (b) states "Substantial

variation above a uniform exposure rate that would satisfy the limits provided in 10

CFR835.206 (a) [i.e., 500 mrem for term of pregnancy] shall be avoided."

HERITABLE EFFECTS

Heritable effects are biological effects that are inherited by children from their parents at

conception. Irradiation of the reproductive organs can damage cells that contain heritable

information passed on to offspring.

Radiation-induced hereditary effects have been observed in large-scale experiments with fruit

flies and mice irradiated with large doses of radiation. Such health effects have not been

observed in humans. Based on the animal data, however, the conservative assumption is made

that radiation-induced hereditary effects could occur in humans.

Radiation-induced heritable effects do not result in genetic diseases that are uniquely different

from those that occur naturally. Extensive observations of the children of Japanese atomic

bomb survivors have not revealed any statistically significant hereditary health effects.

Note: Congenital (teratogenic) effects are not heritable effects. Congenital effects are not

inherited; they are caused by the action of agents such as drugs, alcohol, radiation, or

infection to an unborn child in utero. Congenital or teratogenic effects did occur in children

who were irradiated in utero by the atomic bombs at Hiroshima or Nagasaki.