Bags of Ions

 There are many types of radiation, heat, electromagnetic, microwaves, even sound can be considered a radiation of sorts. But the distinctive damaging qualities of ionizing radiation is exactly as it name states, it is radiation that causes ions, unexpected and unplanned ions.

The building blocks of life are cells - skin cells, bone and muscle cells and more. The cells, in turn are made of molecules. If the molecules are broken by the ionizing particles or rays, the effect on the cell might be insignificant but it could also be catastrophic.

Positively charged atoms of potassium, calcium and magnesium move into and out of cells through electrical charged little holes. Their movement makes our muscles move. The body is very precise about the amount of ions that it wants. 

It is through electrical charge that oxygen is transported to the cells of the body, it is also through electrical charge that the blood protein, heme, carried iron. One of the most amazing things to me is that if the body notices that it needs more iron, it sets up a special assembly line to absorb more from our foods - hormone-like molecules carry messages back and forth - "i need iron." Orders are the carried to the "heme manufacturing unit which also go back to the walls of the bowel including increasing the acid in the stomach". Protein is collected in bone marrow to be constructed into heme and a transfer enzyme brings the iron from the bowel to the marrow. The point of this is that the entire process is very complex.

Enzymes from the thyroid pick up iodine ions and carry them to their thyroid-hormone manufacturing sites. The bowel ionizes foodstuffs in order to absorb them. DNA twists and bends as it responds to the body's needs - or for reproduction - all based upon ions and electrical charges.

Bone marrow, the thin linings of mouth and bowel, are the fastest multiplying cells in the body. Because of this, they are the first to show the effects of ionizing radiation. Reports of anemia and nose bleeds abounded among nuclear workers of all kinds. The permissible level of exposure was about 25 x that allowed today.

It is a little important to remember that, in the entire world only a few people were working on atomic weapons' projects and only a few knew what ionizing radiation was. Scientists knew that it was dangerous, but they rarely conveyed that information to their workers. They probably under-estimated the risk of something that they couldn't see, smell or taste and which rarely gave them immediate side effects. 

For example there was a sign close to Great Bear Lake warning people that they were entering a dangerously radioactive zone in the Northwest Territories. It was written in English. The porters, the men who carried burlap bars of radium ore on their backs, spoke Dene; it is very doubtful that they could read English. (This story was the subject of a film called "Village of Widows" - https://www.youtube.com/watch?v=GSReqj1JX-c). 

The human body is constructed and operated by the formation and destruction of ions and molecules. The body manages these ions to keep the blood at a pH of close to 7.4 and the stomach acid below 3.5. It keeps the potassium level within a mere 2 milliEquivalents - higher and our heart might beat too fast, lower and our muscles feel weak.

To reiterate, the body is made of ions, helping our cells how to hold us upright, thinking, walking and everything else that we do. Ions are electrical charged atoms as in potassium and calcium or charged molecules like heme and other carrying proteins in the blood.

The marvellously fine-tuned manufacturing unit that is a cell can be disrupted when alpha, or beta particles, gamma, cosmic or x-rays pass through the cells. Holes might develop in the cellular walls, enzymes may be broken up and DNA molecules fail to twist appropriately.

The passage of an x-ray or gamma ray can be followed though the body by following the trail of newly formed ions.

The radioactive ray or particle could pass through without ionizing a single atom or molecule in its path - rather unlikely but it could also make such disruptions that the cell can readily repair itself. The cell could repair itself accurately or it could do so making mistakes. If it made mistakes, the errors might be insignificant or fatal to the cell. 

Cells regularly die in our bodies. When a cellular death happens the body sends in a clean-up crew of white blood cells with enzymes and carrier proteins. The body may replace the lost cell from its repertoire of cell replacement material or it may simply continue without it.

The cell can also have its reproductive apparatus damaged. It can lose control of the process - usually reverting to a more primitive cell - and become a tumour when there are enough damaged progeny. Tumours can be benign or metastatic (meaning that they multiply).

Collections of testimonies from survivors of contaminated lands, and thus people who were exposed to chronic low dose radiation tend to tell the same story: they or their families have had cancers, pains in their muscles an bones, strange allergies, intense fatigue, mood and sleep disturbances, weight loss, heart murmurs, a lot of high blood pressure, and always low iron and white cell counts (so they had weakened immune systems). Women had miscarriages, low birth weight babies and 3 x the normal abnormalities.

People close to Chernobyl, people who worked with radium over a hundred years ago, scientists in the Manhattan project, residents of Richland close to Hanford and the Hanford employees themselves - all of these people made the same complaints.

The story is very different for people who receive large doses of radioactivity.

Tickling the Dragon's Tail

Manhattan scientists performed an off-repeated experiment to try to determine the correct amount of radioactive material to make a bomb. They brought two halves of a sphere to within millimetres of one another to study the neutron fluxes that would be required to create an explosion. It was a dangerous move that resulted in deaths of three men.

Louis Slotin was one of them. He was a Canadian physicist from Winnipeg, Manitoba. He was originally working in Chicago with nuclear "piles", the first nuclear power plant built by Enrico Fermi when, in 1942, he was recruited to work on the Manhattan project at its Los Almos lab.

Louis made a name for himself as the "chief armorer" to the United States when he assembled the Trinity bomb.

At that time, scientists had to carry out "criticality" experiments to determine the mass of explosive, the uranium or plutonium, that would form the pit of the bomb. They did this by bringing two reflecting hemispheres together close enough that the neutrons would almost reach criticality, and cause an explosion. These experiments were very dangerous. One of Louis's colleagues had already died from doing so. The dose of radioactivity received the failed experiment was around 5000 mSv, an acute radiation syndrome.

On May 21, 1946, Louis was demonstrating this "criticality" experiment when something slipped and the two hemispheres suddenly came together. Other scientists reported a flash of blue light as the air ionized and a forceful puff of hot air. 

Louis was said to have thrown himself over the hemispheres to protect his colleagues. He knocked them apart ending the criticality. No one was wearing dosimeters measuring their exposure but it was estimated in 1978 that Slotin received at least 11.14 Grey (equivalent to 1114 mSv) but likely much more.

Louis left the lab and immediately vomited several times before going to the hospital. This symptom is common at an exposure of 500 mSv or greater. It is believed to be a direct assault on the central nervous system. Bowel symptoms start on the third day and include violent diarrhea and abdominal pain. As cellular breakdown continues, the kidneys can no longer keep the body in a normal  equilibrium and, as everything is turning into ions, swelling continues. 

In Slotin's case, his left hand actually held the hemisphere that was closest to the neutron criticality and it became grotesquely swollen and excruciatingly painful. The doctors were helpless, there was nothing to do. They could only give him supportive care, painkillers and oxygen when he needed it. 

Louis Slotin died on the ninth day after the accident.

Two of his colleagues from that room also experienced acute radiation syndromes; both recovered to suffer long term sequelae and eventually die of radiation-connected diseases, aplastic anaemia and heart disease. A third observer developed myloid leukaemia.

Other criticality accidents have occurred but only that of Harry Daghlian, Louis's colleague, was due to "tickling the dragon's tail" as scientists referred to the neutron flux experiments. Ironically, Harry's accident occurred with the same plutonium pit that Slotin was using. it became known as the "demon core".

Death occurs in thirty days to half of the people who are exposed to 5000 mSv of radioactivity. As both Harry and Louis knew, their deaths were inevitable. 

This defines the upper limit of exposure. Next - what is the lower limit? Is there a lower level at which ionizing radiation is 'safe'?