ionizing radiation threats

Discussion in 'Back to Basics' started by Tango3, May 17, 2008.


  1. Tango3

    Tango3 Aimless wanderer

    from Jw rawles survivalblog http://www.survivalblog.com/ :heres a good scenario driven primer on radiation exposure( the "gray "is a recent term replacing rad and roengten; equivalized below for us cd shelter dinosaurs):

    How To Prepare for Radiation Emergencies, by KLK


    Scenario 1
    You are sitting at your retreat, enjoying the scenery, when you hear on the radio that there has just been a nuclear weapon that has detonated in a contiguous State . You decide to run into your shelter. After a few days in there, you start to wonder when it might be safe to come out. You also wonder if you would have been better off evacuating and getting as far away from the radiation source as possible.

    A radiation disaster is a scenario for which we must be prepared. It may be from a radiological source, such as a nuclear reactor accident, or from nuclear devices, such as a nuclear weapon.
    Much of what we know about radiation exposure comes from accidents such as Chernobyl [nuclear power plant disaster] and [the bombing of] Hiroshima [and Nagasaki]. With the nuclear reactor accident in Chernobyl (1986), 70% of the contamination fell on 26% of Belarus. 400,000 people were evacuated and 50,000 km squared was restricted and removed from use. The isotopes included Cs137, Cs134, Sr90, I131, and Pu239, with an estimated 114 Million Curies entering the environment. Untoward effects from this accident included 31 initial deaths, 300 injuries and hospitalizations, 150,000 abortions, $ 3 billion spent in emergency response, $500 million spent to compensate Italian farmers, 10,000 reindeer slaughtered, and an increase in cancer (mostly thyroid cancer, many years after the incident).

    It is estimated that if a large US city (population 1 million) was hit by a 10-Kiloton (KT) nuclear device, that it would produce the following casualties:
    >13,000 prompt fatalities
    Approximately 114,000 expectant fatalities (>830 cSv)
    Approximately 90,000 requiring ICU support (530-830 cSv)
    Approximately 141,000 requiring either ICU or minimum care ward (300-530 cSv)
    Approximately 150,000 requiring a minimum care ward (150-300 cSv)
    Approximately 159,000 requiring outpatient therapy (70-150cSv)
    Approximately 128,000 requiring health monitoring (25-70cSv)
    Approximately 212,000 worried [but] well (<25 cSv)
    The healthcare system is not ready or able to cope with this magnitude of casualties. That brings us to: What should you do?
    The mechanism of injury from a nuclear device is 3 fold: blast, heat and radiation. Assuming a 10-KT burst, people within a 0.55 km radius of the explosion fall within a “blast injury circle” and have a high immediate fatality rate. People within a 0.9 km radius of the explosion fall within a “prompt radiation circle”, and people within a 2.1 km radius fall within the “thermal circle” and suffer 2nd degree burns. If you are outside of these 3 circles, you may suffer from radiation fallout. The amount of fallout you are exposed to is determined by 3 factors: length of time exposed, distance from the original explosion, and how much shielding there is between you and the radioactive source.

    To minimize radiation exposure, you will want to reduce your time exposed, increase your distance from the source and have as much shielding as possible. This can lead to a dilemma if faced with this scenario: should you evacuate your retreat (increase your distance from the source), or should you stay and go into your shelter (increase your shielding)? The answer to this question will depend on whether or not you have a shelter, how far away from the initial source you are, the strength of the nuclear device, and the weather conditions. Even if you have a shelter, you may be forced to evacuate due to your proximity to the radiation source (Remember Chernobyl where 50,000 square kilometers were deemed unusable). It can take many months and sometimes years to clean up after a Radiation Event. Most people don’t have shelters that will sustain them for that long. Unfortunately, if faced with this scenario, you will have limited time to make your decision, for if you decide to evacuate you will want to do it immediately to reduce your exposure time, and before the roads get jammed with people. Thus, it would be useful to know a few basic equations to help you make your decision.

    Radiation exposure follows the inverse square law- exposure reduction is proportional to the inverse square of the distance. Radiation is measured in Gray. If the source produces 10 Gy/hour at 1 meter, the exposure will be 2.5 Gy/hour at 2 meters (10 divided by 2 squared). The worst case scenario could produce up to 50-100 Gy/hour at the site of the explosion. With this information, you can calculate your exposure based on how far away you are from the radiation source. You must also keep in mind the weather conditions. If your calculation reveals a total body dose of <0.7 Gy, the radiation effect will be minimal, and you should be safe to stay at your retreat.

    Scenario 2
    You decided to stay at your retreat with some type of shelter, but after 12 hours a family member starts vomiting. Should you take them to the hospital which you know will be full of victims or should you stay isolated?
    The key to treating radiation victims is knowing what dose of radiation they received. All medical decisions are based on the dose estimate.
    There are many ways to determine dose of exposure, most of which require a hospital visit and laboratory tests. Without access to prompt healthcare, the easiest way to determine dose is to record the time from radiation exposure until the time the victim starts vomiting. Then use the information below to estimate the dose the victim received (measured in Gray):

    Time To Onset of Vomiting Post Accident/Terrorist Act


    <table border="1" width="319"> <tbody><tr> <td width="138">Hours to Vomiting</td> <td width="165">Estimated Dose (Gray)</td> </tr> <tr> <td>20</td> <td>0.1</td> </tr> <tr> <td>7</td> <td>0.5</td> </tr> <tr> <td>5</td> <td>1</td> </tr> <tr> <td>2</td> <td>5</td> </tr> <tr> <td>1</td> <td>10</td> </tr> <tr> <td>0.8</td> <td>20</td> </tr> <tr> <td>0.5</td> <td>50</td> </tr> <tr> <td>0.3</td> <td>100</td> </tr> </tbody></table>
    Use that number for the following interventions:
    If they received a dose of < 0.7 Gy, they will not be significantly affected by the radiation and they do not need to be hospitalized.

    If they received a dose of 0.7-5 Gy, their lymphocytes (cells in the blood that fight infection) will dramatically decrease. This happens within the first 1-2 days and puts them at a very high risk of infection. Their hemoglobin and red blood cells will also decrease at 30 days after exposure and they will become very anemic. With good supportive care, the blood counts will recover by 60 days post exposure. Treatment includes IV fluids, antibiotics and colony stimulating factors. These are the people who benefit the most from being admitted to the hospital because they need the colony stimulating factors (which are not able to be stored at a retreat). My advice would be to take them into the hospital. If this is not feasible, they must be quarantined for at least 60 days. If they do not get an infection, there is a good chance they will live.

    If they were exposed to a dose of 6-15 Gy, the predominant effect will be on their gastrointestinal system- this means profuse, bloody diarrhea and dehydration, starting at 5-7 days post exposure. It is also often associated with severe nausea/vomiting and fever. Treatment includes specific antibiotics, GI nutrition, IV fluids and early cytokine therapy for 5 or more weeks. These people will also benefit from hospitalization if feasible. Survival is possible, but unlikely.

    If they were exposed to > 15 Gy, the effect will be on their cardiovascular system and central nervous system. This leads to brain swelling and death within 2-3 days. It is associated with a 100% mortality rate and the best care would be to provide them with pastoral care and to keep them comfortable. There is nothing medically that can be done to save their life.
    Scenario 3
    You decide to make a trip into town to pick up some supplies. It’s around 10 a.m. and you are walking down the street. All of a sudden you hear a loud explosion and see pieces of shrapnel flying. There are casualties all around you from the scrap metal. You are thankful that none of it hit you. Then you hear someone yell “It was a Dirty Bomb!” You think to yourself, “A Dirty Bomb! What should I do?”
    A “Dirty Bomb” is a radiological dispersion device which combines a conventional explosive with a radioactive material. It is not a nuclear weapon, nor a weapon of mass destruction; however, it is a weapon of mass disruption. The impact depends on the type of explosive, amount and type of radioactive material and the weather conditions.

    Immediate deaths or serious injuries would likely result from the explosion itself. It is unlikely that the radioactive material would kill anyone. The radioactive material would be dispersed into the air and reduced to relatively low concentrations. Low level exposure to radioactive contamination could slightly increase your long term risk of cancer (mostly thyroid cancer). There would be significant impact by causing fear, panic and disruption. Clean up would be costly and could take many months.

    Consider this example: In Goiania, Brazil, 1987, 1375 Ci of Cs-137 spread throughout a neighborhood. It was an accident (not a terrorist event), and yet it caused mass panic and fear. Ultimately, 112,000 people were screened, out of which 249 had detectable contamination. Four victims died within four weeks and 20 were hospitalized. Site remediation took months to complete (Oct 1987-March 1988). Can you imagine the impact if it had been a planned event?

    Dirty bombs can expose one to radiation both externally and internally. Internal contamination can occur through inhalation (nose, mouth) or absorption (wound in the skin). The radiation is typically deposited in the thyroid, liver, lung and bone. It is not acutely life threatening.

    When dealing with a victim of radiation contamination, act as if they were contaminated with raw sewage. Protect yourself with clothes, mask, and gloves and use standard medical emergency procedures (Airway/Breathing/Circulation). Decontaminate after the victim is stabilized. Removing their clothing and washing with soap and water is 95%+ effective at decontaminating. Treat with fluids, anti-emetics (anti-nausea), anti-diarrheals and pain medication.

    There are also blocking and diluting agents, but these are isotope specific:
    For Radioactive Iodine (I-131), use Potassium Iodide (KI) - must be given within 4 hours after the exposure, see the dosing chart below
    For Strontium-85 and Strontium-90, use calcium, aluminum, barium
    For Tritium, use ordinary water (force fluids for 3 days)
    For the Transuramics (Plutonium, Americium, Curium, Californium), use DTPA 1 gram intravenously (must be given within 24 hours after the exposure)
    For Cesium, use Prussian Blue 1 gram orally three times a day for three weeks
    There are two problems with the blocking agents: First, you often don’t know what the isotope identity is until after it is too late to administer the blocking agent. There is no easy way to determine which isotopes were included in the bomb and you will need to rely on medical personnel to provide you with this information. Secondly, most of the blocking agents are not readily available. The only exception is KI, which is easily purchased through many of the SurvivalBlog advertisers. You are fortunate if you have DTPA or Prussian Blue stored away, but most people don’t.

    In the absence of knowing what isotopes were in the dirty bomb, my advice would be to have as much fluid as possible (to dilute tritium). I would also take KI if you have some. If I-131 was in the bomb, the KI will protect your thyroid gland (and possible cancer later in life). It must be taken within 4 hours after the exposure. If I-131 was not in the explosive, the KI is safe with minimal side effects. If you decide to take some, use the following dosing chart:
    Adults 18 and older: 130 mg of KI
    Pregnant/Lactating females: 130 mg KI
    Children age 3-18 years: 65 mg KI
    1 month-3 years: 32 mg KI
    Birth-1 month: 16 mg KI

    In summary, the radiological/nuclear threat is real! Mass casualties in your area are possible, but radiation injury is treatable.
    JWR Adds: Some readers might not be familiar with the term Gray--the standard unit of measurement for radiation exposure, that replaced REM (Roentgen Equivalent, Man), and RAD (Radiation Absorbed Dose). For us Bomb Shelter Era dinosaurs, conversion from Grays are as follows.
    1 Gy equals 100 rad
    1 mGy equals 100 mrad
    1 Sv equals 100 rem
    1 mSv equals 100 mrem
    Stocking up on KI tablets is inexpensive, so every family should keep a supply on hand. In 1985, I was stationed in West Germany and was briefly down-wind of Chernobyl. At the time I wished that I had some KI available! Anyone that lives in an urban area should have a Nuk-Alert "key fob" radiation detector. That way you won't have to wait for word from someone else to determine whether or not a nearby bomb explosion was a dirty bomb. Nuk-Alerts are available from several SurvivalBlog advertisers.
     
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