March 29, 2011 Vol. 60, No. 7

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OREGON PUBLIC HEALTHOGY DIVISIONPUBLICATION • OREGON OF THE PUBLIC HEALTH HEALTH AUTHORITY DIVISION ORECON DEPATMENT OF HUMAN SERVICES EVERYTHING YOUR PATIENTS WANT TO KNOW ABOUT RADIATION* (*AND AREN’T AFRAID TO ASK) n March 11 at 2:46 p.m. local demolished the containment structure risk to human health, however, comes time† a*magnitude-9.0 earth- around the reactor, and dispersed from internal exposure. quake struck 109 miles east of radioactive material thousands of feet Internal exposure results from: O • Inhaling particles in contaminated Fukushima off northeastern Honshu, into the atmosphere, spreading medi- Japan. In addition to destroying many cally significant amounts of it up to air, or 2 communities and leaving more than 500 km away. Nothing like that hap- • Swallowing particles in contaminated 20,000 dead or missing, the earth- pened in Fukushima. food or water. quake and resulting tsunami knocked Three types of ionizing radiation: Age: Children are growing and developing, and as a consequence are out cooling systems at the six-reactor alpha, beta and gamma, are relevant. at higher risk of adverse health effects Fukushima Daiichi nuclear power From high school chemistry you will recall that when a radioactive sub- from radiation. (This is true not only plant. As this issue goes to press, the stance decays, it can release alpha in exposures that might result from an conditions at the plant remain serious particles, i.e. two protons and two accidental radiation release, but also but appear to be coming under con- neutrons; beta particles, i.e. electrons; from radiological imaging.) trol. Radiation releases have endan- or gamma rays, i.e. photons. (For more ISOTOPES BEHAVING BADLY gered workers attempting to control information on these, type “IAEA ra- 1 Several radioactive fission prod- the situation at the plant, but in the dior” into an Internet search engine.) ucts could be released from a reactor, absence of a large, explosive release but three are of particular concern: of radiation, the 4,643 miles between iodine 131, cesium 137, and strontium How much is 100 nanorem? Astoria and Fukushima make it very 90. These are produced in quantities unlikely that Oregon will see levels th sufficient to cause illness in the setting of radiation that pose a health risk • 1/500,000 of the dose acquired of a large radiation release, and they from this event. As expected, routine from rocks, bricks and sun in a can “volatilize” and spread if a large typical day monitoring of environmental samples explosion leads to high-altitude, broad • 1/100,000th of the radiation received has detected trace amounts (about dispersion. In addition, their half-lives from a typical chest x-ray 100 nanorems) of iodine 131 and are long enough that they could stick • 1/50,000,000th of the anticipate dose around to do some damage. “Nuclear other radioactive isotopes from Japan at which potassium iodide is rec- half-life” refers to the amount of time — well below any level of concern ommended for infants (5 rems) (Box); but your patients may have • After 80,000 years of exposure at it takes for half of the isotope to decay questions nonetheless. In this issue this level, potassium iodide is into other elements. This is different of the CD Summary, we review basic recommended from the biological half-life, which is information about ionizing radiation, the amount of time needed for half the the health effects it can produce, and isotope load to be excreted from the The duration of exposure is also body. what we can do about it should a risk important. Cumulative exposure is the 131 for significant exposure ever arise I is easily absorbed by the body key risk factor for the chronic health if it is ingested or inhaled, and con- here in Oregon. effects of radiation, and many of the centrates in the thyroid gland. Its RADIATION RISK FACTORS commonly used measures to gauge nuclear half life is only 8.1 days, but its The risk of illness from radiation health effects describe degree of expo- accumulation in the thyroid can lead depends upon the amount and type sure per unit time. to several forms of thyroid disease, of radiation, the duration of exposure, The route of exposure — how radio- including cancer.3 the route by which exposure occurs, active particles come into contact with 137Cs has a half-life of 30 years. The and the age of the person exposed. the body — affects exposure duration body handles it like potassium, so if it The amount of radiation released and has an independent effect on risk is ingested, it is distributed through- in an event depends on how much of radiation-induced illness. out the soft tissues. It can increase the radioactive material is present and on External exposure occurs when par- risk for a variety of soft-tissue cancers.4 the force with which it is dispersed. ticles are released into the air and then 90Sr (half-life 29 years) is handled by The disaster at Chernobyl, Ukrainian fall onto surfaces. Radioactive isotopes the body like calcium. Though 70%– SSR in 1986 featured run-away fission, can be easily washed from skin and 80% of it is excreted, the remaining followed by a large explosion that other surfaces, but if left on the skin in 20%–30% of ingested 90Sr is incorpo- † large amounts and for prolonged peri- *9:46 P.M. on March 10 Pacific Standard Time ods, they can lead to burns. The main The CD Summary (ISSN 0744-7035) is published biweekly, free of CD SUMMARY charge, by the Oregon Health Authority, Office of Disease Prevention and PERIODICALS Epidemiology, 800 NE Oregon St., Portland, OR 97232 March 29, 2011 POSTAGE Periodicals postage paid at Portland, Oregon. Postmaster—send address changes to: Vol 60, No. 7 PAID CD Summary, 800 NE Oregon St., Suite 730, Portland, OR 97232 Portland, Oregon

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rated into bones and teeth. Significant birth defects in the child, although the FOR MORE INFORMATION exposure is associated with increased greatest risk in this setting is miscar- Advise your patients to call our risk of leukemia, bone cancer, and riage. information line at 877-290-6767; cancers of the soft tissues adjacent to • In some cases, radiation may cause or to check our web site: http://pub- bone.5,6 mutations in a parent’s DNA, lead- lic.health.oregon.gov/Preparedness/ HEALTH EFFECTS: ACUTE AND ing to genetic illness in the child of an CurrentHazards/Pages/index.aspx CHRONIC exposed person. REFERENCES Acute Radiation Sickness occurs COUNTERMEASURES TO AVOID 1. International Atomic Energy Agency. Fu- following exposure to a massive dose EXPOSURE AND ILLNESS kushima nuclear accident update log. www. iaea.org/newscenter/news/tsunamiupdate01. of radiation in a short time, as hap- We won’t be needing these in the html. Accessed 25 Mar 2011. pens near a nuclear bomb explosion or foreseeable future, but there are a few 2. International Atomic Energy Agency. Fre- very close to a severe nuclear power simple strategies that could be used quently asked Chernobyl questions. www. plant accident. Historical examples of to decrease the likelihood of exposure iaea.org/newscenter/features/chernobyl-15/ victims of such exposure include the and illness, should the need for them cherno-faq.shtml. Accessed 20 Mar 2011. 3. CDC. Radioisotope brief: Iodine-131. www. first responders at Chernobyl; resi- arise. These include staying indoors bt.cdc.gov/radiation/isotopes/pdf/iodine.pdf. dents of Hiroshima and Nagasaki; and (“sheltering in place”) if radiation Accessed 20 Mar 2011. Louis Slotin and Harry Daghlian, two levels become high; or evacuating if 4. U.S Environmenal Protection Agency. Ce- Manhattan Project scientists who were recommended by public health author- sium. www.epa.gov/radiation/radionuclides/ exposed to acute, lethal doses of radia- ities. Persons exposed to >3,000 mil- cesium.html. Accessed: 20 Mar 2011. 137 5. U.S Environmenal Protection Agency. tion during experiments at Los Ala- lirems of Cs can take Prussian blue, Strontium www.epa.gov/radiation/radio- 7 mos, New Mexico, during 1945–1946. a prescription medicine that binds nuclides/strontium.html. Accessed 20 Mar Acute radiation sickness begins cesium in the gut, speeding its elimi- 2011. within minutes to hours of exposure nation from the body and decreasing 6. Agency for Toxic Substance and Disease and can include: its biological half-life from 110 days to Registry. Interaction profiles: introduction 8,9 www.atsdr.cdc.gov/interactionprofiles/IP-08/ • Nausea, vomiting and diarrhea about 30 days. Persons exposed to ip08-c1.pdf. Accessed 20 Mar 2011. 131 • Skin burns or rashes I can take potassium iodide to satu- 7. Alsop S. The strange death of Louis Slotin. • Bone marrow toxicity, with subse- rate the thyroid with iodine, thereby Saturday Evening Post, Mar. 6, 1954. quent bleeding and risk of infection decreasing uptake of the radioactive 8. CDC. Prussian blue fact sheet. www.bt.cdc. • Death isotope. The recommended threshold gov/radiation/prussianblue.asp. Accessed Chronic Health Effectsfrom radia- 21 Mar 2011. for treatment in pregnant women 9. U.K. Health Protection Agency. Use of tion exposure reflect a person’s total and in children <18 years of age is an Prussian Blue for decorporation of radio- exposure over time. This includes ra- anticipated 131I exposure of ≥5,000 mil- caesium. www.hpa.org.uk/web/HPAwebFile/ diation from the natural environment, lirems. Due to decreased sensitivity to HPAweb_C/1274091555595. Accessed 21 from x-rays or CT scans, and from the carcinogenic effects of this isotope, Mar 2011. other sources. 10. U.S Food and Drug Administration. Guid- thresholds for treatment in adults are ance: potassium iodide as a thyroid blocking 10 • Radiation exposure over time can higher. agent in radiation emergencies. www.fda. increase the risk for leukemia and CONCLUSIONS gov/downloads/Drugs/GuidanceCompli- cancers of the breast, thyroid, and You can reassure your patients that anceRegulatoryInformation/Guidances/ ucm080542.pdf. Accessed 20 Mar 2011. lung, among others. the risk to Oregonians, and, hence, the • Exposure of a pregnant woman in the need for any of these countermeasures first trimester can increase the risk of in response to the situation in Japan, is negligible.