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Diagnosis is typically made based on a history of significant radiation exposure and suitable clinical findings. [3] An absolute lymphocyte count can give a rough estimate of radiation exposure. [3] Time from exposure to vomiting can also give estimates of exposure levels if they are less than 10 Gy (1000 rad). [3]
Radiation hormesis is the conjecture that a low level of ionizing radiation (i.e., near the level of Earth's natural background radiation) helps "immunize" cells against DNA damage from other causes (such as free radicals or larger doses of ionizing radiation), and decreases the risk of cancer. The theory proposes that such low levels activate ...
It is distinct from acute radiation syndrome, in that it occurs at dose rates low enough to permit natural repair mechanisms to compete with the radiation damage during the exposure period. Dose rates high enough to cause the acute form (> ~0.1 Gy/h) are fatal long before onset of the chronic form. The lower threshold for chronic radiation ...
Radio frequency (RF) energy at power density levels of 1–10 mW/cm 2 or higher can cause measurable heating of tissues. Typical RF energy levels encountered by the general public are well below the level needed to cause significant heating, but certain workplace environments near high power RF sources may exceed safe exposure limits. [7]
Excess relative risk is the rate of disease in an exposed population divided by the rate of disease in an unexposed population, minus 1.0. [2] This means that the risk of cancer from irradiation in the first trimester is 28% higher than in the third trimester.
Increased Risk of Solid Cancer with Dose for A-bomb survivors, from BEIR report.Notably, this exposure pathway occurred from essentially a massive spike or pulse of radiation, a result of the brief instant that the bomb exploded, which while somewhat similar to the environment of a CT scan, is wholly unlike the low dose rate of living in a contaminated area such as Chernobyl, where the dose ...
Of special interest to NASA is the dependence on age at exposure of low-LET cancer risk projections. The BEIR VII report prefers models that show less than a 25% reduction in risk over the range from 35 to 55 years, while NCRP Report No. 132 [ 6 ] shows about a two-fold reduction over this range.
Most commercial electronics can survive this radiation level. [21] 16,000 1.6 × 10 ^ 4: Acute: Highest estimated dose to Chernobyl emergency worker diagnosed with acute radiation syndrome [15] 20,000 2 × 10 ^ 4: Acute: 2,114,536: Interplanetary exposure to solar particle event (SPE) of October 1989. [22] [23] 21,000: 2.1 × 10 ^ 4: Acute-