DOSES
The extent and time period of exposure to a dose is important to determine the likely biological damage to a human ****** A healthy body has a given capacity to repair damage from radiation. Thus a full body exposure to a big dose over a short time is generally more harmful because the body cannot keep up with repairs, than a full body exposure of a small dose over a long time which the body usually can repair as it occurs.
Ingesting (breathing, eating) radioactive particulate, such as radioactive dust blown by the wind from a nuclear plant fire or atomic bomb test, is very harmful. If a significant quantity of particulate stays in parts of the body, such as radioactive iodine in the thyroid, it will radiate and may cause:
- local tumors that may become cancerous
- growth of cancerous blood cells
- birth defects
- neurological defects in the brain that hinder future mental development
0.1 mSv/yr: increased risk of death from radiation induced cancer about 1 in 1,000,000; i.e., one millimort
100 mSv/yr: death of radiation induced cancer increased by 0.8%, two 100 mSv doses 1.6%, etc.
1,000 to 2,000 mSv for about one hour: 0 to 5% fatal
8,000 to 30,000 mSv for about one hour: 100 % fatal