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Biological Effects

We live in a radioactive environment. We are subject to background radiation all the time and the normal levels are well known. Radiation is in the air we breath, the food we eat, and the places in which we live and work.


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There is evidence to suggest that unless radiation exposure reaches ten (10) times the normal background level, there is no harm to humans from radiation. Furthermore, there appears to be evidence that radiation at or near the normal background level may be beneficial to, and even necessary, for life.

For low levels of radiation exposure (under 10,000 mrem), the biological effects are so small they may not be detected. The body’s natural repair mechanisms often repair any damage to the cells before any effect is felt or detected. This protective effect of low levels of radiation is called “radiation hormesis.”

Too much radiation, like too much of anything, is harmful.

The effects of too much radiation (over 50,000 mrem) can range from mild gastrointestinal problems (such as nausea and vomiting), to changes in the blood, to damage to the central nervous system.

High levels of radiation dose have caused cancers (leukemia, breast, ovarian, pancreatic etc) and led to death.


  • Most people who died at Hiroshima did not die from the radiation; most died from the blast of the bomb and subsequent fires.
  • Studies have shown that cellular cultures (protozoa) could not grow normally when they were deprived of background radiation (Luckey TD.)
  • Between 1978 and 1987, 108,000 nuclear submarine workers were compared to 700,000 other shipyard workers. There were 24% fewer cancers among those exposed to low-doses of radiation.
  • The Colorado Plateau, with higher background radiation levels, has 15% fewer cancers than the national average.


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