POSSIBLE EFFECTS OF RADIATION

Radiation may strike a vital part of the cell, like the nucleus, or a less-vital part, like the cell membrane.

When radiation strikes a cell, the following effects can occur:

some cells are damaged
most cells repair the damage
some cells die as a result of the damage
some cells may mutate and grow





Factors that Determine Biological Effects

Area of the body exposed
Total dose received
Dose rate
Type of radiation
Individual sensitivity
Cell sensitivity

Acute Dose

An “acute” dose is received in a short period of time (e.g., seconds to days)

For the same total dose, an acute dose is more damaging than a chronic dose because cells don’t have time to repair damage between “hits”

After a large acute dose, the body can not repair or replace cells fast enough, and physical effects may occur

Death can occur if the dose is high enough An “acute” dose is received in a short period of time (e.g., seconds to days)

Effects of Acute Whole-Body Doses

>50 Sv - CNS damage; death within 2-3 days
> 5 Sv - Gastrointestinal System damage
4.5 - 6 Sv - Lethal Dose (50/30)
2 - 5 Sv - Hematopoietic System damage
1 - 2 Sv - Radiation sickness
.25 - .50 Sv - Slight blood changes
.5 Sv - Annual whole-body dose limit

Effects of Acute Extremity Doses

Burns
Necrosis
Loss of fingers

Chronic Dose

A chronic dose is typically a small amount of radiation received over a long period of time.

Typical examples of a chronic dose are:

The dose received from natural and man-made background radiation
The dose received from occupational exposure

Body is better equipped to tolerate chronic doses

Effects of Chronic Doses

Chronic effects can result from radiation doses received over a long period of time.

May not appear for years after exposure
Effects are too small to measure below a cumulative dose of 0.10 Sv
The higher the cumulative dose the greater the risk of a chronic effect
Increased risk of cataract formation
Increased risk of developing cancer

Individual Sensitivity

Some individuals are more sensitive to radiation than others

Age, genetic make-up, and overall health can have an affect on how the body responds to radiation exposure