“Recommended limit for volunteers averting a major nuclear escalation - 500 mSv (according to the International commission on Radiological Protection)
Recommended limit for volunteers rescuing lives or preventing serious injuries - 1000 mSv (according to the International commission on Radiological Protection)
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Below is a list of signs and symptoms likely to occur when a human is exposed to acute radiation (within one day), in mSv:
0 to 250 mSv - no damage
250 to 1,000 mSv. Some individuals may lose their appetites, experience nausea, and have some damage to the spleen, bone marrow and lymph nodes.
1000 to 3000 mSv - nausea is mild to severe, no appetite, considerably higher susceptibility to infections. Injury to the following will be more severe - spleen, lymph node and bone marrow. The patient will most likely recover, but this is not guaranteed.
3,000 to 6,000 mSv - nausea much more severe, loss of appetite, serious risk of infections, diarrhea, skin peels, sterility. If left untreated the person will die. There will also be hemorrhaging.
6,000 to 10,000 mSv - Same symptoms as above. Central nervous system becomes severely damaged. The person is not expected to survive.
10,000+ mSv - Incapacitation. Death. Those who do survive higher radiation doses have a considerably higher risk of developing some cancers, such as lung cancer, thyroid cancer, breast cancer, leukemia, and cancer of several organs.”
http://www.medicalnewstoday.com/articles/219615.php
Umbilical cord stem cells come from the umbilical cord -- something that used to be discarded when a baby has been born.
Research with embryonic stem cells has basically been a total failure -- so I would not want to be treated by this government-waste-of-money-project. Besides that, one has to kill an innocent baby to harvest embryonic stem cells.
Somewhat off topic, but leukemia has been treated and cured using umbilical stem cells...