Shortening the time of exposure, increasing distance from a radiation source and shielding are the basic countermeasures (or protective measures) to reduce doses from external exposure.
Time: |
The less time that people are exposed to a radiation source, the less the absorbed dose. |
Distance: |
The farther away that people are from a radiation source, the less the absorbed dose. |
Shielding: |
Barriers of lead, concrete or water can stop radiation or reduce radiation intensity. |
To reduce doses from intake of radioactive substances, the following basic countermeasures can be considered:
-
shortening time of exposure to contaminants;
-
preventing surface contamination;
-
preventing inhalation of radioactive materials in air; and
-
preventing ingestion of contaminated foodstuffs and drinking water.