Heritable Effects - hdbk1130cn20077

DOE-HDBK-1130-98

Module 2 Biological Effects

Instructor's Notes

Delayed Effects

Delayed effects may result from either a

single large acute overexposure or from

continuing low-level chronic exposure.

Cancer in its various forms is the most

important potential delayed effect of

radiation exposure. Other effects noted

include cataracts, life shortening and, for

individuals exposed in the womb, lower IQ

test scores.

Heritable Effects

A heritable effect is a physical mutation or trait

that is passed on to offspring. In the case of

heritable effects, the parental individual has

experienced damage to some genetic material in

the reproductive cells and has passed the

damaged genetic material onto offspring.

Heritable effects from radiation have never

been observed in humans but are considered

possible. They have been observed in

studies of plants and animals.

Heritable effects have not been found in the

77,000 Japanese children born to the

survivors of Hiroshima and Nagasaki (these

are children who were conceived after the

atom bomb -- i.e., heritable effects).

Studies have followed these children, their

children, and their grandchildren.

Factors affecting biological damage due to exposure to

radiation

Total dose

In general, the greater the dose, the greater the

potential for biological effects.

Dose rate (how fast)

The faster the dose is delivered, the less time the

body has to repair itself.