Acute and Chronic Radiation Dose

DOE-HDBK-1130-98

Module 2 Biological Effects

Instructor's Notes

1) The body of most cells is made up primarily of water.

When ionizing radiation hits a cell, it is most likely to

interact with the water in the cell. One of the byproducts

of radiation- induced ionization of water is hydrogen

peroxide. Hydrogen peroxide can damage cell atomic

structures.

2) Ionizing radiation can also hit the nucleus of the cell.

The nucleus contains the vital parts of the cell, such as

chromosomes. The chromosomes determine cell

function. When chromosomes duplicate themselves, the

chromosomes transfer their information to new cells.

Radiation may cause a change in the chromosome that

does not affect the cell.

3) Damage to chromosomes and other cell structures can be

repaired. In fact, our bodies repair a very large number

of chromosome breaks every day (References 7 and 10).

c. Cells are damaged and operate abnormally

1) Cell damage may not be repaired or may be incompletely

repaired. In that case, the cell may not be able to

function properly.

2) It is possible that a chromosome in the cell nucleus could

be damaged but not be repaired correctly. If the cell

continues to reproduce, this is called a mutation and may

result in cancer.

d. Cells die as a result of the damage

At any given moment, thousands of our cells die and are

repla ced by normal functioning cells. However, the

radiation damage to a cell may be so extensive that the

cell dies prematurely.

Acute and Chronic Radiation Dose

Potential biological effects depend on how much and how

fast a radiation dose is received. Radiation doses can be

grouped into two categories: acute and chronic dose.