Richard Denton, MD
Disclaimer: I am a medical doctor and will concentrate on the medical aspects. I have no conflict of interest as some nuclear physicists might who are paid by the nuclear industry.
Radiation is one of the six crises that this Platform addresses; each one could annihilate civilization as we know it. Radiation could do so in either an acute or chronic manner. The acute effects would come from a major accident, miscalculation, or terrorist attack or an actual nuclear war. The chronic effects are killing by inducing cancers and other medical conditions.
Radiation exposure is of course related to the other five global threat scenarios. Radiation is interconnected as part of a nuclear war that would immediately kill millions from radiation. A nuclear bomb is not just a bigger better bomb but emits radiation that kills locally and at a distance over time. Because of its power, it would put dust and smoke into the stratosphere that would cause a decrease of the sun’s penetration. A “nuclear winter” would result, causing death of millions by famine. Some people suggest that nuclear power is “green” —even the answer to climate change. But nuclear power plants could be a target of terrorists using cyberwarfare or crashing an airliner into a reactor.Expand article
Radiation is like Yin and Yang. It has detrimental effects—causing cancers, etc. — but also beneficial effects, as in helping make diagnoses through X-rays and nuclear imaging and also in treating cancers. Ionizing radiation has the ability to break apart molecules like DNA. There are different types of ionizing radiation: alpha and beta are weak energy but potent if taken internally, while X-rays and gamma radiation have strong energy and can kill acutely people as well as cancers, or can be used externally in diagnosis.
There are several principles that apply to radiation in humans. Radiation accumulates in the body and acts over time. Even small doses of radiation can become significant if one is exposed to them all the time. Radiation comes from several sources: background (about one to three milliSieverts, although it can be higher in specific regions) that affects us all, such as from the sun, or the ground such as radon gas that is the number two cause of lung cancer in Canada. We are also exposed individually when we get an X-ray or fly in an airplane.
If a food source that has been contaminated with radiation is eaten, it is absorbed by the organism that devours it. Thus, radiation is concentrated up the food chain. We humans are at the top of the food chain. We thus concentrate radiation over time.
People vary in their susceptibility, with fetuses being the most vulnerable, then children and women.
Radiation affects rapidly dividing cells and these are the dividing quickly in fetuses and children. Timing is important. Just as Fetal Alcohol Syndrome occurs when alcohol is ingested at the time an embryo is developing, and cannabis may affect the developing brain of people younger than twenty five, radiation acts similarly on different age groups, inducing miscarriages, mutagenesis, or teratogenesis.
Radiation also affects specific organs, depending on the radioactive substance that is absorbed. Iodine 131 affects the thyroid, whereas strontium 90 is analogous to calcium and is taken up by bone and thus affects the bone marrow and blood.
Some people believe in a hypothesis called homesis that says that small doses of radiation may be beneficial in causing mutations that will stimulate the immune system and that some mutations may improve our species. This is held by very few non-medical people. As medical doctors, we believe that there is a linear graph such that even small amounts of radiation over time can be harmful. We should try to minimize our exposure.
Safety limits are designed by people and are dependent more on politics, to prevent panic of the masses as opposed to being based on science. Limits of radiation vary from country to country and even in local municipalities. It is set to vary, depending on the job that one does. It is allowed for workers in nuclear plants to receive up to 100 mSv. (MilliSeverts) per year, while the limit for the general population is ten mSv.
Here are the effects of acute radiation on humans: The effects vary with the size of the dose — amount of exposure to the radiation. With 50-100 mSv (milliSieverts), there are changes in blood chemistry. At 500 mSv, one develops nausea, and then fatigue, followed by vomiting at 700 mSv., followed by hair loss and then diarrhoea over the following 2-3 weeks, as the most rapidly dividing cells are affected first. At 1000 mSv. you start bleeding. At 4,000 mSv, there may be death in 2-3 months. At 10,000 mSv., there is death within 1-2 weeks with destruction of the intestinal system and bleeding. At 20,000 mSv., the neurologic system is affected resulting in loss of consciousness, and death within hours to a few days.
Here are the effects of chronic radiation on humans: miscarriages; mutagenic (changes in the genetic material, usually DNA but also RNA, leading to mutations such as Down’s syndrome), teratogenic (which disturbs the development of a fetus, resulting in congenital malformations that can be passed down to future generations); cancers such as leukaemia, thyroid, breast, brain, pancreas; hardening of the arteries, leading to strokes and heart attacks; cataracts; kidney damage; and acceleration of the overall ageing process.
We also have a gradation of severity of nuclear accidents; The International Nuclear Event Scale (INES) rates the severity of accidents on a logarithmic scale from 1 to 7 with 7 being the worst; a major accident; (Chernobyl April 1986, and Fukushima March 2011). A level 6 serious accident was the Kyshtym disaster at the Mayak Chemical Combine in the Soviet Union in September 1957 at a nuclear waste reprocessing plant. Level 5, accidents with wider consequences, include Windscale fire at Sellafield on October 1957 in the United Kingdom, which caused a fire with graphite and uranium in a military air cooled reactor; the Three Mile Island on March 1979 nuclear power plant; Chalk River, December 1952, when the reactor core was damaged; and the Goiânia accident in Brazil in 1987 when a caesium chloride radiation source was taken from an abandoned hospital.
Please see also the following paper, which expands on the above summary:
- Radiation and Nuclear Fuel (PDF; 65-page download)