Radiation 101

There is a great deal of conflicting information about radiation and it’s effects around at the moment. This ranges from overly complacent to hysterical with not much of anything in between.

This article is not about Three Mile Island, or Chernobyl or Fukushima, it is just about radiation in general, the different types, how it causes damage, what you can do to mitigate some of the issues it creates and the signs and symptoms of radiation poisoning.

The reason for this is simple…conflicting information. It is impossible to comment on specifics without having seen the readings, without knowing exactly what went, or what is going on at the site, and without reading the medical reports detailing the issues those people close to these incidents have had. The doses of radiation required to cause injury seems to vary from country to country, which is nonsense of course, a small amount of radiation can be deadly, and for that reason these supposed ‘safe doses’ have been omitted.

TYPES OF RADIATION

Essentially there are two types of radiation, non-ionising and ionising. Background radiation, that we are all exposed to on a daily basis is non-ionising. It comes from sources both natural and man-made such as naturally occurring radio waves, light and microwaves. In general it causes very low level damage that the body responds to and repairs on an on going basis.

Ionising radiation is more of a problem. It usually involves larger doses at one time, and is responsible for more cellular damage than non-ionising radiation. It comes from medical imaging primarily, but can come from industrial sources, nuclear accidents and nuclear weaponry. Gamma ray bursts and lightening are two forms of naturally occurring sources of ionising radiation.

It is of course possible, especially in the case of nuclear accident where a population at some distance from the source is exposed to low level but sustained dosing of ionised radiation rather than  the initial large dose experienced by those close to the incident. The duration and severity of exposure is also determined by the type of release. An explosive release will give rise to the possibility of radioactive particles travelling on the winds that circle the globe, passive release is far less likely to distribute radioactive particles in this manner.

Even having a massive explosion of radioactive material does not mean it will definitely have effects on health half a world away. The effects of radiation at a distance depends on many factors, the atomic weight of the particles, the heavier they are the quicker they will ‘fallout’. This fallout can be affected by debris present that’s  mixed with the particles. Hiroshima and Nagasaki seen covered in ash  is what most people understand by the term fallout. Material destroyed by the explosive power of the bomb was sucked up and mingled with the radioactive particles caused by detonation of the nuclear warhead, this fell to earth as radioactive ash. The type of particle emitted will alter the effects felt by populations, and finally, the half life of the element that has been ejected needs to be taken into consideration. Half-life is the term used to describe the time it takes half of the radioactive nuclei to undergo radioactive decay. After two half lives 1/4 of the original amount remains, after three half lives 1/8 of the original amount remains and so on.

IONISING RADIATION PARTICLES

Alpha. (particulate)

Alpha particles are the lowest energy ionising particles. In a passive release they only travel a few inches from the source. In an explosive release it is impossible to say how far they will travel, but either way they do little damage at the cellular level provided they are not ingested or get into the body via an open wound. They are not powerful enough to get through unbroken skin. When they do hit a penetrable object they dissipate their energy quickly and cause damage immediately at the entry point rather than travelling through the object causing damage as they go. Ingestion of these particles is dangerous. Ingested Alpha particles can lead to lung cancer at  a later stage. Examples of Alpha particles are Radon,Radium, Uranium and Thorium. All of these particles are stopped by paper, clothing and even a layer of dust.

Beta (particulate)

Beta particles are high energy, high speed electrons. They travel further than Alpha particles after a passive release, two or three feet, and can penetrate human skin up to just under an inch. They dissipate their energy quickly and can cause damage over a wider area than Alpha particles due to the level of penetration. Babies and young children suffer more damage than adults from Beta radiation simply due to the fact that they are smaller and proportionally more of their body is affected by each particle that penetrates the skin. Beta particles hitting the body can cause a wide variety of illnesses ranging from skin burns  to  bone cancer. Low level but long term exposure can cause general malaise for many years without the cause being readily apparent. The endocrine system and glands are particularly susceptible beta particle damage. Some examples of Beta  particles are Strontium 90, Iodine 131, Iodine 132 and iodine 133. These particles can be stopped by most solid objects. They cannot for example penetrate glass.

Gamma (electromagnetic waves)

Gamma radiation is the most biologically destructive. These waves can travel many feet in air and can penetrate through skin and several inches of tissue exposing most if not all organs to radiation damage. Cellular damage is guaranteed and cancers of almost any organ may appear years after the event. Babies and children are severely affected from Gamma radiation and will suffer direct effects faster than adults. An example of Gamma radiation is potassium 40. Gamma radiation can penetrate solid objects with ease. A full inch of lead is the minimum thickness required for non therapeutic radiation, of known dose such as x-rays. Several feet of concrete would be needed to protect from Gamma radiation.

The mode of action of these particles on the body is complicated. Some behave like calcium and concentrate in the bones. Others behave like potassium and can affect kidney function. There are major variations in the way radiation affects one person and not another, even if those people are in the same house and belong to the same family. Doctors and scientists have not  worked out why this is and research continues to find the answers to the many questions radiation poses. What is known is that radiation of all kinds weakens the immunity of the vast majority of people who are contaminated by it and that cells with a high turnover, such as white blood cells which fight infection, and crypt cells that line the intestine are often the first cells to be affected. Bone marrow where red blood cells are actually produced is particularly prone to radiation damage.

SYMPTOMS OF RADIATION SICKNESS

The symptoms of radiation poisoning are many and varied. It is possible to suffer from radiation sickness at a level that does not produce more than one or two of the most minor known symptoms it is all dependant on the dose received and the duration it is received over. For this reason radiation poisoning can be medically considered to be either acute or chronic. The classic symptoms of acute radiation poisoning are:

Nausea

Vomiting

Diarrhoea

Fatigue

These would be followed by:

Headache

Shortness of breath

Tachycardia (rapid heartbeat)

Inflammation of the mouth and throat

Tooth and gum disease

Hair loss

Dry unproductive cough

Reddening/burning of the skin

Chest pain and heart inflammation

Permanent darkening of the skin

Spot bleeding under the skin

Haemorrhage

Anaemia

It should be noted that not all symptoms will appear in all victims. Where large exposures have occurred-usually above 10 gray death often occurs in 2-4 weeks. Those who survive this dose for six weeks will generally recover but are highly likely to present with serious radiation induced illness at some point in the future.

There is little you can do to mitigate the effects of radiation after exposure. It goes without saying it is far better to avoid exposure in the first place.

Doubling your distance from the source reduces your exposure by 16 times, this is known as the inverse square law.

Being underground, in a custom built or other type of shelter, providing the shelter is thick enough or buried deep enough will protect you from radiation.

Potassium iodide, a stable salt of iodine can prevent the thyroid gland from absorbing radioactive iodine.

Bentonite clay (fullers earth) is edible and has been shown to draw some radioactive particles out of the intestine, and to reduce the amount of these particles in water if used as a filter medium.

A word about MOX

MOX refers to mixed oxide fuel. There are two isotopes of uranium, uranium 235 and uranium 238. There are four isotopes of plutonium, plutonium 239, 240, 241, and 242. Neutron capture changes the basic components, uranium 235 into 238 and the same with plutonium, plutonium 239 becoming one of the other isotopes due to neutron capture, the amount of capture decides the isotope formed. The use of this  fissile material the mixed oxides reprocessed from spent fuel rods increases the amount of electricity it is possible to produce by up to 22% more than a standard reactor.

The half life of plutonium 239 is 24,000 years. Based on half life calculations 1/4 of the original amount of plutonium released will still exist 48,000 years after the event.

By way of comparison, iodine 131  has a half life of eight days. Using the same calculation, 1/4 of the original amount would remain 16 days after the event.

Finally….

Reports are circulating of babies born in the United States, with birth defects due to the effects of radiation from Japan. This seems unlikely. I am not saying those babies do not exist, and I am not saying it is not an environmental issue that caused the defects they were born with, but it is highly unlikely Fukushima radiation was the cause though Chernobyl radiation or leaks from more local nuclear facilities is a definite possibility. As the time lapse between Fukushima and the present increases it becomes more likely that birth defects as a direct result of the accident will become more commonplace.

For a woman to become irradiated to that point she would have been visibly sickened herself, with some of the symptoms of radiation sickness being present. These women would have to have suffered high dose radiation exposure during the first trimester of pregnancy when cell division in the foetus is still forming the structures of the body.

This does not seem to be the case. It is interesting to note that although I have access to an large amount of medical literature I cannot find a reference to human birth defects in the United States or Europe being medically attributed to radiation from the Fukushima disaster.

Birth defects in the future from a low level long term exposure to ionising radiation is a very plausible possibility due to  structural changes in the DNA caused by the earlier radiation exposure.

There is a massive amount of information about radiation available to the general public and this article barely scratches the surface of this very complex subject. If you decide to explore the subject further it is advisable to gather information from reliable scientific sources.

Take care

Liz