SubClinical Effects / Minimum Detectable Levels

Medicine's inability to detect disease or organ damage through normal clinical procedures does not guarantee that no damage has/is occuring. This is especially true with regards to children. Cancers that will occur later in life and minor tissue damage that will effect future growth, creating disease and early death, due to exposure to toxins are both examples of non-detectable injury (through ordinary means).
Minimum Detectable Levels of radioisotopes (through ordinary means) can only relate that the tests used do not detect the toxins, not that no damage has/is occuring at low levels of exposure. Dr. Busby (link below) discusses heart disease and death due to heart attack in children exposed to low levels of radiation (20-30 Bq/Kg Cs-137), and says that when this is happening to children in a given area then the rest of the children should be evacuated because, though their damage is subclinical, damage is still occuring which will most likely show up later in life.
http://www.youtube.com/watch?v=E4Kkuo-IK-A