Types
of Ionizing Radiation Exposure
There are two general
types of radiation exposure, which may occur alone or simultaneously:
external irradiation (whole body irradiation or localized
irradiation), and contamination (external or internal)
External Irradiation
occurs when all or part of the body is exposed to electromagnetic radiation
(gamma rays or x-rays) from an external source. The degree of
injury depends upon the dose of radiation received (Dose = Exposure
Time X Exposure Rate.)
External Contamination
occurs when radioactive material or debris (sometimes referred to as fallout)
is deposited on the body and clothing. Generally, external contamination
is not a serious medical problem as long as contaminated clothing is removed
and the material is washed off of the body quickly.
Internal
Contamination occurs when radioactive materials are inhaled, ingested,
or absorbed through open wounds. The assessment and management
of internal contamination is more difficult than for external contamination
but is not an emergent condition.
Protection
From Ionizing Radiation
The cardinal
rule of protection against radiation is time, distance, and shielding.
| Time: |
The
shorter the amount of time you spend near the radiation source, the
less radiation exposure you receive. |
| Distance:
|
The
farther away you are from a radiation source, the less exposure you
receive. |
| Shielding:
|
Increasing
the shielding around a radiation
source, or around you, decreases exposure. |
Treatment
Alert |
| Casualties
who have been irradiated are not radioactive themselves
unless radioactive material (source material or fallout) has been
deposited on or in their bodies. |
|
Never
delay major trauma care
for radiological decontamination! |
Scene
Control and Responder Protection
- The incident commander
will determine how much radiation exposure will be allowable for individual
responders and will set the maximum allowable cumulative dose.
- All responders
must be equipped with direct-reading
individual dosimeters.
- When any responder’s
total dose exposure reaches
the maximum allowable dose as set by the incident
commander, that responder must leave the site
immediately and cannot return until the site has
been decontaminated and is opened to the general
public. There are no exceptions to this rule.
Triage
of Radiation Casualties
Since the clinical
effects of all but the most severe radiation exposures are delayed, the
clinical presentation of exposed casualties will be primarily related
to conventional injuries.
- Normal trauma
triage procedures should be employed, but early closure of simple wounds
is mandatory in irradiated casualties.
- Depending on the
severity of the casualty’s condition
and triage status, decontamination can be done
before, during, or after initial stabilization.
|
