Article Figures & Data
Figures
- FIGURE 1.
This figure shows dose curves that correspond to the dose models described in text. Data are measured at high dose levels and then, using curve-fitting techniques, extrapolated to estimate low dose portion of the curve. Low dose data points shown on these curves are thus estimated, not measured.
Tables
H2O (molecule) + ionizing radiation → H+ + OH− = (hydroxyl, free radical) Recombination of: H+ + H+ → H2 = hydrogen gas (not a problem) H+ + OH− → H2O = water (not a problem) Antioxidants can recombine with the OH− free radical and block hydrogen peroxide formation. If not, then the 2 hydroxyl ions could do the following: OH− + OH− → H2O2 = hydrogen peroxide formation H2O2 → H+ + HO2− = unstable peroxide HO2− + organic molecule → stable organic peroxide stable organic peroxide → lack of essential enzyme → eventual cell death is possible Hematologic Syndrome Dose: Approximately 1–10 Gy (100–1000 rad) Clinical Symptoms: General injury of blood-forming cells in bone marrow, which increases with increasing dose, leading to pancytopenia. This results in bleeding, anemia, hemorrhage, malaise and severe, often fatal, infection. Treatment: 0–1 Gy (0–100 rad)—Reassurance 1–2 Gy (100–200 rad)—Reassurance and hematologic surveillance 2–6 Gy (200–600 rad)—Blood transfusion and antibiotics 6–10 Gy (600–1000 rad)—Consider bone marrow transplant Without treatment, no one has survived a single abrupt dose of 5 Gy (500 rads) or higher. It is possible to survive the hematologic syndrome with a bone marrow transplant, but at higher doses all subjects will die from the gastrointestinal syndrome. Gastrointestinal Syndrome Dose: Approximately 2–50 Gy (200–5000 rad) Clinical Symptoms: Nausea, vomiting and diarrhea (NVD), prolonged diarrhea, dehydration, electrolyte imbalance, lethargy, anorexia, death above 10 Gy (1000 rads) with no treatment. Treatment: 2–6 Gy (200–600 rad)—Blood transfusion and antibiotics 6–10 Gy (600–1000 rad)—Consider bone marrow transplant 10–50 Gy (1000–5000 rad)—Maintenance of electrolyte balance At about 2 Gy (200 rads), classic radiation sickness (nausea, vomiting and diarrhea [NVD]) may begin because of radiation injury to the gastric and intestinal mucosa. Central Nervous System Syndrome Dose: >50 Gy (>5000 rads) Clinical Symptoms: Ataxia, convulsions, lethargy, coma, death Treatment: Sedatives Cockroach 50 Gy (5000 rads) Rabbit 8 Gy (800 rads) Goldfish 7.5 Gy (750 rads) Rat 6 Gy (600 rads) Mouse 4.5 Gy (450 rads) Monkey 4.5 Gy (450 rads) Humans ∼2.5–4.5 Gy (250–450 rads) Subclinical Range Therapeutic Range Lethal Range Acute Radiation Exposure in Sieverts (rems) → 0–1 Sv (0–100) 1–2 Sv (100–200) 2–6 Sv (200–600) 6–10 Sv (600–1000) 10–50 Sv (1000–5000) >50 Sv (>5000) Treatment required Reassurance Reassurance and hematologic surveillance Blood transfusion and antibiotics Consider bone marrow transplant Maintenance of electrolyte balance Sedatives Overall treatment plan None needed Observation Effective Therapy Promising Palliative Palliative Incidence of vomiting None 5% at 1 Sv (100 rem); 50% at 2 Sv (200 rem) 100% at 3 Sv (300 rem) 100% 100% 100% Delay time prior to vomiting N/A 3 h 2 h 1 h 30 min 30 min Leading organ affected None Blood-forming tissue Blood-forming tissue Blood-forming tissue GI tract CNS Characteristic Sign(s) None Mild leukopenia Severe leukopenia; hemorrhage; hair loss above 3 Sv (300 rems) Severe leukopenia; infections; erythema Diarrhea; fever; electrolyte imbalance Convulsions; tremor; ataxia; lethargy Critical period post exposure N/A N/A 4–6 wk 4–6 wk 5–14 d 1–48 h Prognosis Excellent Excellent Good Guarded Hopeless Hopeless Incidence of death None None 0–80% 80%–100% 90%–100% 90%–100% Cause of death N/A N/A Hemorrhage and infection Hemorrhage and infection Circulatory collapse Respiratory failure and brain edema Prodromal Phase: (Prodromal means running before) Signs and symptoms include NVD, hair loss above 3 Gy (300 rads), skin erythema above 6 Gy (600 rads) Latent Phase: Period of no signs or symptoms Manifest Phase: NVD returns, hematologic syndrome, GI Syndrome, CNS syndrome signs and symptoms return to prodromal levels or worse. Recovery Phase: If good treatment is provided and the affect individual received less than a 10-Gy (1000 rads) dose, recovery is possible after the Manifest Phase. Source/Radiopharmaceutical Effective/Whole Body Dose cGy (rads) Average annual dose to U.S. population from all sources 0.36 Natural radon exposure 0.027 X-ray diagnosis 0.039 Nuclear medicine 0.014 Consumer products 0.010 Cosmic radiation 0.027 Terrestrial radiation 0.028 Radiopharmaceutical cGy/mCi (rads/mCi) 67Ga citrate 0.26 201T1 chloride 0.21 18F FDG 0.04 123I iodide 0.03 99mTc sulfur colloid 0.019 99mTc MIBI 0.017 99mTc DTPA 0.016 99mTc DISIDA 0.016 99mTc MAA 0.015 99mTc HMPAO 0.013 99mTc pertechnetate 0.011 99mTc MDP 0.007 99mTc MAG3 0.007 Region of Body Annual Limit in cSv (rems) Whole-body 5 Extremities (hand, forearm) 50 Skin 50 Any internal organ 50 Lens of the eye 15 Cumulative lifetime dose = 1 cSv (rem) × age.
Fetal dose = 0.5 cSv(rem)/9 mo, not to exceed 0.05 cSv(rem)/mo.
General public in nonrestricted areas = 0.002 cSv(rems)/h or 0.1 cSv(rem)/y.
