Radiation injury history and symptoms
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Signs and Symptoms
Table of exposure levels and symptoms
Dose-equivalents are presently stated in sieverts:
0.05–0.2 Sv (5–20 REM)
No symptoms. Potential for cancer and mutation of genetic material, according to the Linear no threshold model (LNT model): this is disputed (Note: see hormesis). A few researchers contend that low dose radiation may be beneficial.    50 mSv is the yearly federal limit for radiation workers in the United States. In the UK the yearly limit for a classified radiation worker is 20 mSv. In Canada, the single-year maximum is 50 mSv, but the maximum 5-year dose is only 100 mSv. Company limits are usually stricter so as not to violate federal limits. 
0.2–0.5 Sv (20–50 REM)
No noticeable symptoms. Red blood cell count decreases temporarily.
0.5–1 Sv (50–100 REM)
Mild radiation sickness with headache and increased risk of infection due to disruption of immunity cells. Temporary male sterility is possible.
1–2 Sv (100–200 REM)
Light radiation poisoning, 10% fatality after 30 days (LD 10/30). Typical symptoms include mild to moderate nausea (50% probability at 2 Sv), with occasional vomiting, beginning 3 to 6 hours after irradiation and lasting for up to one day. This is followed by a 10 to 14 day latent phase, after which light symptoms like general illness and fatigue appear (50% probability at 2 Sv). The immune system is depressed, with convalescence extended and increased risk of infection. Temporary male sterility is common. Spontaneous abortion or stillbirth will occur in pregnant women.
2–3 Sv (200–300 REM)
Moderate radiation poisoning, 35% fatality after 30 days (LD 35/30). Nausea is common (100% at 3 Sv), with 50% risk of vomiting at 2.8 Sv. Symptoms onset at 1 to 6 hours after irradiation and last for 1 to 2 days. After that, there is a 7 to 14 day latent phase, after which the following symptoms appear: loss of hair all over the body (50% probability at 3 Sv), fatigue and general illness. There is a massive loss of leukocytes (white blood cells), greatly increasing the risk of infection. Permanent female sterility is possible. Convalescence takes one to several months.
3–4 Sv (300–400 REM)
Severe radiation poisoning, 50% fatality after 30 days (LD 50/30). Other symptoms are similar to the 2–3 Sv dose, with uncontrollable bleeding in the mouth, under the skin and in the kidneys (50% probability at 4 Sv) after the latent phase.
4–6 Sv (400–600 REM)
Acute radiation poisoning, 60% fatality after 30 days (LD 60/30). Fatality increases from 60% at 4.5 Sv to 90% at 6 Sv (unless there is intense medical care). Symptoms start half an hour to two hours after irradiation and last for up to 2 days. After that, there is a 7 to 14 day latent phase, after which generally the same symptoms appear as with 3-4 Sv irradiation, with increased intensity. Female sterility is common at this point. Convalescence takes several months to a year. The primary causes of death (in general 2 to 12 weeks after irradiation) are infections and internal bleeding.
6–10 Sv (600–1,000 REM)
Acute radiation poisoning, near 100% fatality after 14 days (LD 100/14). Survival depends on intense medical care. Bone marrow is nearly or completely destroyed, so a bone marrow transplant is required. Gastric and intestinal tissue are severely damaged. Symptoms start 15 to 30 minutes after irradiation and last for up to 2 days. Subsequently, there is a 5 to 10 day latent phase, after which the person dies of infection or internal bleeding. Recovery would take several years and probably would never be complete.
Devair Alves Ferreira received a dose of approximately 7.0 Sv (700 REM) during the Goiânia accident and survived, partially due to his fractionated exposure.
10–50 Sv (1,000–5,000 REM)
Acute radiation poisoning, 100% fatality after 7 days (LD 100/7). An exposure this high leads to spontaneous symptoms after 5 to 30 minutes. After powerful fatigue and immediate nausea caused by direct activation of chemical receptors in the brain by the irradiation, there is a period of several days of comparative well-being, called the latent (or "walking ghost") phase. After that, cell death in the gastric and intestinal tissue, causing massive diarrhea, intestinal bleeding and loss of water, leads to water-electrolyte imbalance. Death sets in with delirium and coma due to breakdown of circulation. Death is currently inevitable; the only treatment that can be offered is pain therapy.
Louis Slotin was exposed to approximately 21 Sv in a critical accident on 21 May 1946, and died nine days later on 30 May.
At this dose the skin can be damaged. Here is a photo of a man who received a 10 to 20 Gy gamma whole body dose as a result of an industrial accident. He died about 10 days after the photo was taken, about 30 days after the event.
More than 50 Sv (>5,000 REM)
A worker receiving 100 Sv (10,000 REM) in an accident at Wood River, Rhode Island, USA on 24 July 1964 survived for 49 hours after exposure, and an operator receiving between 60 and 180 Sv (18,000 REM) to his upper body in an accident at Los Alamos, New Mexico, USA on 30 December 1958 survived for 36 hours; details of this accident can be found on page 16 (page 30 in the PDF version) of Los Alamos' 2000 Review of Criticality Accidents .
Cutaneous Radiation Injury
The signs and symptoms of CRI are as follows:
- Intensely painful burn-like skin injuries (including itching, tingling, erythema, or edema) without a history of exposure to heat or caustic chemicals
- Note : Erythema will not be seen for hours to days following exposure, and its appearance is cyclic.
- A tendency to bleed
- Possible signs and symptoms of ARS
As mentioned previously, local injuries to the skin from acute radiation exposure evolve slowly over time, and symptoms may not manifest for days to weeks after exposure. Consider CRI in the differential diagnosis if the patient presents with a skin lesion without a history of chemical or thermal burn, insect bite, or skin disease or allergy. If the patient gives a history of possible radiation exposure (such as from a radiography source, x-ray device, or accelerator) or a history of finding and handling an unknown metallic object, note the presence of any of the following: erythema, blistering, dry or wet desquamation, epilation, ulceration.
Regarding lesions associated with CRI, be aware that,
- Days to weeks may pass before lesions appear;
- Unless patients are symptomatic, they will not require emergency care; and
- Lesions can be debilitating and life threatening after several weeks.
Medical follow-up is essential, and victims should be cautioned to avoid trauma to the involved areas.