*Radiation Sickness*
Signs and Symptoms of Radiation Exposure
The short-term consequence of overexposure to nuclear radiation has been called "radiation sickness." Signs and symptoms associated with the digestive system are those seen earliest and at the lowest exposure levels. The chart below shows the exposures that will cause about 50% incidence of various symptoms from radiation sickness. This prediction is based on clinical data from irradiated hospital patients.
Estimated Single Radiation Exposures
That Will Cause 50% Incidence of symptoms
| Signs and symptoms (In 50% of Patients) | Single exposure | 95% confidence range |
| Loss of appetite | 180 Roentgens | 150-210 (R) |
| Nausea | 250 (R) | 220-290 (R) |
| Fatigue | 280 (R) | 230-310 (R) |
| Vomiting | 320 (R) | 290-380 (R) |
| Diarrhea | 360 (R) | 310-410 (R) |
The blood forming organs, mainly the bone marrow, are the most sensitive parts of the body, but observable signs of blood changes develop later and are more evident at higher exposures. These changes result in lowering of the resistance to infection through depression of the body’s immune system. When fatalities occur, they are often the result of complicating infection. At progressively higher levels of exposure, the gastrointestinal tract and then the central nervous system are affected.
Radiation sickness is not a communicable disease. It cannot be transmitted to others. In this respect, it is similar to food or chemical poisoning. Indeed, The problem is not protecting others from the radiation victim, but protecting the radiation victim from others.
Another point to be noted in the table is that the symptoms that occur earliest and after lowest exposures (particularly nausea and vomiting) are also symptoms of simple anxiety, stress, and fear. Moreover, one or two persons exhibiting these symptoms in a crowded, closed environment can induce nausea and vomiting in others. Since radiation injury itself is not painful or otherwise apparent until symptoms of sickness appear, random reactions to the stress of the emergency could be erroneously interpreted as radiation sickness.
Levels of sickness
Unapparent radiation injury occurs when the exposure is less than about 50R. As shown below. Level 1 radiation sickness occurs in the exposure range of 50R to 200R. At this level, less than half the people so exposed will experience nausea and vomiting within 24 hours. There are either no subsequent symptoms or, at most, only easy fatigability. At this level, less than 5% will require medical care for radiation injury. Most can perform their customary tasks. Deaths that occur are caused by complications such as blast and thermal injuries or infections and debilitating disease.
Summary of Relationship between Exposures
And Level of Radiation Sickness
| Exposure Range | Type of Injury | Probable Mortality Rate Within 6 months of Exposure |
| 0-50 R | No observable signs or symptoms | none |
| 50-200 R | Level 1 sickness | Less than 50% |
| 200-450 R | Level 2 sickness | Less than 50% |
| 450-600 R | Level 3 sickness | Less than 50% |
| More than 600 R | Level 4 & 5 sickness | 100% |
At level 2, more than half of those affected will vomit soon after exposure and will be ill for several days. This will be followed by a period of one to three weeks when there are few or no symptoms. At the end of this latent period, loss of hair will be seen in more than half, followed by a moderately severe illness due primarily to damage to blood forming organs. Most of the people in this group require medical care. More than half will survive, with the chances of survival obviously being better for those who received the smaller doses; early illness does not necessarily make survival more unlikely.
The Level 3 illness is a more serious version of that described for Level 2. The initial period of illness is longer, the latent period shorter (one or two weeks), and the ensuing illness is characterized by extensive hemorrhages and complicating infections. At this level, fewer than half will survive in spite of the best medical care, with the chances of survival being poorest for those who have received the largest exposure.
Level 4 is an accelerated version of Level 3. Everyone at this exposure level will begin to vomit soon after exposure and this will continue for several days or until death, which will occur before the end of the second week, and usually before the appearance of hemorrhages or loss of hair.
Level 5 is an extremely severe illness in which damage to the brain and nervous system predominates. Symptoms, signs, and rapid prostration come on almost as soon as the dose has been received. Death occurs in a few hours or days. Illness of this type has been seen after accidents involving exposure to gamma radiation in excess of several thousand roentgens.
This information came out of old FEMA Radiological Monitoring training books. I feel this information might come in handy in the near future.
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