Every day radiology

Comrades, I have updated this blog with tags, and a search box, so that you now may search for articles by using terms and tags instead of going through every post seeking for a specific subject.

This post was going to be only about the above, as I'm currently writing articles for my exhibition, but then something else came up. It's not so much about Chernobyl as it is about radiation.

415 bq by the window.

Recently, I met professor Janne Wallenius, who lent me his Gamma Scout. A Gamma Scout is nowadays probably the most commonly used popular device for measuring radiation, which was also used by my group during our Chernobyl expedition in May. I borrowed it to get a chance to learn more about how it works, and also check the readings on various places. Starting out in Gothenburg city, the average background radiation showed to be approximately 0,22 µSv/h. Returning to my home outside the city, the readings showed an average of 0,16 µSv/h, and then I went inside my house, where the readings immediately increased. I quickly realized that this must be a so called Radon house After having checked the numbers displayed over a few hours, making a note of the wide fluctuations displayed (between 0,15 and 0,32 µSv/h), I decided to switch the GS into reading bequerel instead and I'm glad I did...  

Here in Sweden, the MRL in resident buildings is 200 bq/m³ and the readings were a solid 447 bq in the middle of the room. No fluctuations. Today I measured another apartment, where the readings were even higher: 547 bq. On Monday I will contact the housing company and demand them to investigate this further, because I cant be 100% sure that these readings are  exactly what I think they are, but if they are and I was to make a point here, I'd say it's healthier to live in a house in Pripyat. 

The Sacrifice

The last few days have gone by without anything having happened here. What can I say - each day is one day closer to the opening of my exhibition, and the preparation work is piling up, but unfortunately that still doesn't mean that the day gets more than 24 hours. In the nearest future I probably won't be able to post here every day, but still I'll try to do it as regularly as possibly. After all - the project continues.

Being done with the civil updates, I want to draw your attention back to my previous posts about radiation and the effect and damage it may have on the human body. Shortly after the first part was published, a woman gave me a tip about a Chernobyl documentary called The Sacrifice, a 26 minutes film by the Swiss journalist Wladimir Tchertkoff and Emanuela Andreoli about liquidators of Chernobyl and the consequenses they suffered after performing their duties at work. This film, made in 2003, focuses on the health condition of a few liquidators years after the Chernobyl disaster - the consequenses of absorbing large doses of radiation. These liquidators, and their families, tell about bodies decomposing whilst still alive. 

About radiation, part 3: Closing up

There's too much about radiation to be dealt with in a simple blog like this - after all, it's a science of its own, and a subject that we still don't know everything about.

In the two previous posts, I tried to cover the most basic things about the effects of radiation on the human body, but I realize, and apologize for it, that I forgot to explain the very basics of radioactivity itself; what it is and how it occurs.

Radioactivity is the result of the process of spontaneously decaying atom nuclei emitting ionizing radiation. Alpha, beta, and gamma radiation are the most common types of radiation. 

Alpha radiation is constituted of so called alpha particles, like nuclei of Helium atoms: Two neutrons and two protons. This kind of radiation is easily blocked by other matters - just a sheet of paper is enough -  and can for example not penetrate the outer skin layer. Thus, alpha radiation is only dangerous if in direct contact with living cells, which may happen through ingestion on alpha contaminated food or inhalation of alpha radiationg particles.

Beta radiation and beta particles consists of electrons and/or positrons formed during beta decay. If ingested, it's less dangeous than alpha radiation, as a beta particle has lesser mass than an alpha particle. Beta radiation has the ability to penetrate human tissue with a reach of 1 cm (which, if you've read the previous post, you remember may cause severe burns). This kind of radiation can also change the structure of struck molecules and mutate them. A few millimeters of Aluminium will shut out beta radiation.

Gamma radiation consists of photons and is also recognized as the electromagnetic radiation emitted by atom nuclei. Gamma rays are the most penetrative kind of rays connected to radioactivity. It may be blocked out by a concrete wall or lead. Gamma radiation is what causes what we refer to as radiation sickness. It causes damage throughout the body and increase the risk of cancer to occur.

Now  we know more about what may happen if exposed to radiation in different doses, but if exposed to a degree where it becomes a health problem, how can it be treated?

ARS symptoms don't develop immediately, as it takes time for the mutated DNA to produce enough proteins to make an obvious change in body chemistry and structure, and  unfortunately there is no known way to treat this, as doctors and scientists are unable to repair damaged DNA. All they can do is treating the symptoms.

Concerning cancer inflicted by radiation, it's treated just like cancer with no connection to radioactive exposure, by cytotoxin or more commonly, by radiotherapy. 

About radiation, part 2: How it may affect the human body

Most of the radiation around us comes from Radon.

Radon (Rn) is a gas, which in itself is harmless, but when it decays, it emits ionizing radiation, primarily in the form of alpha particles.

The most frequently occuring isotope of Radon is Rn-222, which is formed as the Uranium in the bedrock decays, and thus Radon exists naturally in the ground. It can also exist in building structures and even in drinking water, the latter due to the bedrock surroundings of the groundwater.

Especially Radon in residential buildings is in some countries a problem: As you just read, the gas itself isn't dangerous, but during decay, the Polonium ions 218 and 214 are formed. These stick to dust and smoke particles which then stick to the lungs when inhaled. Inside the lungs, the chain of decay continues, and this alpha decay causes damage to the breathing organs and increases the risk of lung cancer to develop.

Smokers, ex-smokers and passive smokers are for clear reasons exceptionally exposed to these risks. A non smoker; i.e an individual who has never smoked, the risk of Radon induced cancer is approximately 0,41%, but for an active smoker, the risk lies at about 9,7%. World wide, Radon is estimated to cause 3-14% of the total number of cases of lung cancer, and in Sweden, the number of cases is approximately 500 per year.

Now with these numbers dealt with, and a brief introduction to that ionizing radiation may induce cancer, the next logical question should be about how and why it happens.

The cell nucleus, containing the DNA molecule, is very sensitive to radiation, so exposed to such, it may lead to an uncontrolled division of cells, which in turn may lead to cancer. The cells that divide fastest, for example the cells of the bone marrow and the mucus membranes of the digestive organs, which are constantly regenerated, are more easily affected by ionizing radiation than for example brain cells. With the knowledge of ionizing radiation have accumulated to this day, it's been calculated that a one time exposure to a dose of 20 mSv increases the risk of developing cancer with 0,1%. It may take up to 20 years before cancer induced by low doses of radiation occur.

May I now bore you with some information about some of the fallout elements of the Chernobyl disaster and how they affect the human body? I thought not, here goes.

Iodine-131 has a half life of only 8 days and the human body's absorption of it can be blocked by ingesting Iodine pills. Absorbed Iodine is concentrated to the thyroid and when the Iodine is radioactive, the decay causes damage to the thyroid, but by taking supplements such as mentioned Iodine pills, providing the body with a maximum amount of Iodine, which reduces the uptake of the element.

However, the younger an individual is at the time of exposure, the greater are the risks of developing thyroid cancer. Children and teenagers, who are not fully physically developed, take more damage  from Iodine-131 than adults, who doesn't seem to show any significant difference in tyroid disease, compared to an unexposed group of equvalents.

In Kiev, Iodine supplements were handed out to the population 14 days after the disaster. By this time, they were pretty much useless.

Caesium-137 is a radioactive isotope of Caesium, which is formed by nuclear fission, and having a half life of 30 years, it means that areas exposed to Chernobyl fallout are still more or less contaminated.  Caesium-137 hasn't existed "naturally" on Earth for many billion years, but the occurance of the element in modern times,  is caused by man and  Caesium-137 is evenly distributed in the body, although with a higher concentration in muscular tissue, differently from...

Strontium-90, which goes straight to the skeleton and teeth, as the human body absorbs it as if it was Calcium. Calcium and Strontium have chemical similarity, but this unstable isotope of Strontium may induce bone cancer and other bone related disorder and diseases.

Ironically enough, Strontium-90 is used in cancer therapy, due to its long half life (28 years) and beta emission.

Photo from http://www.freeinfosociety.com

Lets now summarize in what other ways radiation may affect the human body.

The blood system

Even relatively low doses of radiation may inflict a reduction of  lymphocytes (white blood cells). These have the function of keeping the body clean from infections and without them, this part of the individiual's natural physiological defence is reduced, and the individual simply becomes more exposed to infections. For example flu like symptoms in a person who's been exposed to radiation, may be indicating a reduction as such, and the symptom can sometimes last for up to ten years. Patients with an insufficient amout of lymphocytes in their blood system are more susceptible to leukemia (blood cancer).

The brain

is due to its none reproductive cells, was  believed not to be affected by radiation, but  when it comes to absorption of high doses, as for example the cases of the firefighters and liquidators I mentioned in my previous post, damage to the central nervous system was recorded, and nowadays we also know that there's a connection between high doses of radiation and brain tumours.

The heart

Moderate doses of radiation may cause damage to capillaries and thereby also the heart. As the small blood vessels burst, the blood isn't transported properly to the heart, which increases the risk of cardiac arrest, which was the cause of death for many liquidators.

The reproductive organs

Ionizing radiation doesn't only affect the vital organs of the human body, but also the reproductive systems, (which  due to that also the cells of these divide very fast) are very susceptible to radiation damage. Many victims of radiation poisoning become sterile, males in particular. Radiation also affect fetuses and after the Chernobyl disaster a large number of abortions were obtained throughout Europe, due to fear of the radiation from the Chernobyl fallout. Among the deleterious effects on fetuses are miscarriage, birth defects, mental retardation, growth retardation (whilst still in uterus) and development of cancer.

The skin

Chernobyl firefighter, Photo from http://www.sxolsout.org.uk/

Ionizing radiation can inflict burns often refered to as gamma or beta burns. Beta radiation isn't able to  penetrate deeply into the body but manifest like shallow skin burns, but if exposed to intense beta radiation, indications of burns manifest in 24-48 hours with an itching or  burning sensation, and after 7-21 days, the actual symptoms appear as erythema, increased pigmentation, then desquamation/epilation and skin lesions. 

Concerning victims of the Chernobyl disaster, this was a serious issue. Of 115 liquidators treated in Moscow, 30% had severe burns covering signifigant areas of the body surface. This exposure was often caused by radioactive water (and recently there's been similar cases in Fukushima, Japan) Some firefighters suffered internal beta burns after inhalation of massive amounts of radioactive smoke and out of the 28 first deaths, 16 liquidators and firefighters had skin injuries listed among the causes. 

The skeleton 

The non growing portions of the bone are relatively resistant to radiation, but for growing individuals such as children and teenagers, large doses of radiation may retard the growth and development of the bones, and the bone marrow, where blood cells are formed, is generally at a greater risk of being damaged, inducting leukemia. and bone cancer. Exposure to Strontium-90 means an increased risk.

The thyroid

Also the thyroid is very susceptible to radiation and thyroid cancer is the most frequently occuring consequence. Above, I mentioned how the exposure to Iodine-131may affect especially young individuals, but if you want more in-depth information, a good article is to be found here.

Ionizing radiation affect more or less the entire body in different ways, but all of them lead to damage, disease or death. I'd like to spend more time digging further into this, but I'm afraid I do not have that time.

About radiation, part 1: Acute Radiation Syndrome (ARS)

It's all around us, its everywhere - just like Kraftwerk points out in their song Radioaktivity: 

"Radioactivity - it's in the air for you and me"

 ...and this is true. Every day we're exposed to radiation. Living on Earth, the magnetic field of the planet protects us from dangerous gamma radiation from the space that surrounds us all, but even down here, we're still exposed to radiation from various sources: Radiation also comes from the bedrock, our TV sets, computers and a lot of other utilities and devices we have invented and even from ourselves. Like all living creatures on this planet, we radiate.

However, the gathering term of "radiation" is generally mistaken for ionizing radiation, which is a term for the kind of radiation that has the characteristics of knocking electrons from their atoms, which turns the atoms into ions. Ionizing radiation, to put it shortly, may be electromagnetic radiation (gamma, roentgen and ultraviolet radiation) or particle radiation which is constituted by atoms or parts of atoms moving in a "flow". Examples of this is alpha, beta and neutron radiation. 

Chernobyl liquidator in 1986. Photo from Belarus.com

But what happens when the human body is exposed to ionizing radiation? 

As the energy of the [ionzing] radiation reaches the body, electrically charged elements are formed, and these are the very ions. They trigger the culturing of new, strange elements in the tissue which may cause irreparable damage to the cells. The constitution of hydrogen peroxide easily adapts to the molecules of the human body and  is known to alter their chemical structures.

Still to this day, we know more of acute radioation syndrome (ARS) than we may be able to determine happens to the human body if exposed to relatively small increased levels of ionizing radiation during a longer time span. It's recorded that such a thing increases the risk of developing cancer, but there are still many questions that need to be answered within that area, as it's also been proven that people living on sites where the bedrock emit higher levels of radiation, are generally healthier than their equivalents in places where the bedrock is less radioactive, so it goes without saying that we still have a lot to learn about radiation.




Acute Radiation Syndrome

Radiation, nowadays, is measured accoring to the Sievert (Sv) units, but there's another unit for measuring how much ionizing radiation the human body has absorbed, and this is measured in so called Grays (Gy). 1 Gy is equivalent to 1 Sv The threshold of ARS is defined between 0,5 - 1,0 Gy - having exceeded this limit, the well known symptoms of nausea, vertigo and vomiting occur.  If being exposed to what is regarded as a mild dose (1-2 Gy) you may expect symptoms of nausea and vomiting withing six hours, and the later effects, such as weakness and fatique,  will occur approximately three to five weeks later. 

 If having absorbed more than 6 Gy, most symptoms, nausea, headache, vomiting, fever and diarrhea will occur within a matter of hours, and then follows the so called latent period. Also at mild exposure, there is a latent period followed by mild leukopenia (Leukopenia means a decrease of white blood cells in the human body, which increases the risk of infections.) fatique and weakness, but the mortality is low: Regardless if being treated or not, the mortality is lower than 5% and those who die from mild absorption are especially old individuals, or individuals of already poor health, but at absorption over 6 Gy, death is almost certain if the individiual is not treated and even if treated, the mortality is between 50-100%. 

Workers on the roof or reactor block 4, 1986. Photo: guardian.co.uk

The higher the absorption, the shorter is the latent period and absorbing over 8 Gy, the latent period will be absent and death follows within 2-14 days. 


Even though no one seem to be able to determine or tell for sure, about the levels of radiation that some of the Chernobyl liquidators were exposed to, we can almost be sure of that they absorbed far over 8 Gy (some firefighters were estimated to having been exposed to approximately 750 Roentgen per hour, but the true numbers should exceed this. 750 R = 7.5 Sv = 7.5 Gy), why they died very shortly after the exposure, over a short time span having suffered multiple severe ARS symptoms.


ARS symptoms at absorption over 8 Gy are: Nausea and vomiting, diarrhea, intense headache, high fever, electrolyte disturbance, shock and disturbance of the central nervous system.