A particle of plutonium 239 revealed by autoradiography. The black star in the middle of the picture shows tracks made by alpha rays emitted from a particle of plutonium 239 in the lung tissue of an ape. The alpha rays do not travel very far but once inside the body they can penetrate more than 10,000 cells within their range. This set of alpha tracks (magnified 500 times) occured over a 48 hr period. The plutonium 239 particle that emitted them has a half life of 24,400 years. [Lawrence Radiation Laboratory, Berkeley California, September 20, 1982.]
Note that Pu238 (half life of 89.7 years) is 272 times hotter (more active) than Pu239. It decays much faster so it's biological effects are stronger in proportion. Pu decay pathways are all radioactive.
1 kg. Pu238 was released from a navigational satellite launch accident over the Indian Ocean in 1964. The plutonium dispersed remains detectable in the southern hemisphere.
This illustration is taken from Robert Del Tredici's book Working in the
Fields of the Bomb - published in 1987. It shows a
plutonium particle emitting ionising radiation. The tracks are about 35
microns (5 cell diameters) but this is a two dimensional view of
a 3D tissue event, which in fact occurs continuously in biological space.
Like a land mine that never stops exploding, it is perpetually
damaging and destroying cells.
Since it has a short emission path - it is difficult to detect outside the body. Customary histology and autopsy studies do not detect it so plutonium in the living body is likely to be an occult, undetected and unreported factor. In man, it is particularly well situated to cause harm since it lodges especially in the body-wide reticulo-endothelial system. Here it can impair and kill cells of the immune system leading to immune deficiency and eventually leukemia. Leukemia is found down wind from Winscale which has been processing nuclear waste and extracting plutonium since 1952. Winscale/Sellafield is still pumping "nuclear effluent" into the Irish Sea every night. Much of this is carried by Northeast Atlantic currents up the coast of Norway to the Arctic Ocean where it accounts for 20% of measured current Arctic plutonium pollution. There was an incident at Sellafield when the cooling system failed and divers found the water intake plugged with monster jelly fish. Fishing is forbidden close to Sellafield where there are high environmental plutonium levels in Irish Sea sediment.
The first plutonium bomb (Fat Man, Nagasaki, August 1945) comprised 15 kg of Pu239. Of this only 1.5 kg fissioned, and the remainder (13.5 kg) was vaporized. It has been shown that within two years the Nagasaki plutonium became evenly distributed around the northern hemisphere and random sampling in stable ice layers in the Canadian Arctic for instance showed traces. It is inferred that from this time, Pu239 could gain access to biological systems and to the food chain. Some plutonium would be found in sediments, but it forms water soluble hydroxyls, and hydroxy halides which can be absorbed into living systems.
Plutonium has been shown to gain access to marine life and food chain in varying proportions. It is taken up most actively by plankton, and is also rapidly excreted by them, but plankton feeders such as fish larva, herring, pilchard, anchovy and whales are susceptible to ingesting it. It is also taken up significantly by bottom feeding marine creatures that live on or disturb sediment. These include starfish, octopus, flatfish and cod. Effects on fish might include reduced fecundity, deformities, increased disease susceptibility and reduced longevity. This would be seen as falling size and numbers of fish that is - loss of ocean bounty. World fishing accounts for double the food mass of land husbandry.
It hs also been shown to become incorporated into tree rings. Plutonium entry into edible plants appears possible but evidence is hard to find. Plutonium is so biotoxic that its chemical toxicology - which would probably resemble lead - is overshadowed by its radiotoxicity.
There are of course other radioactive products produced by nuclear technology. The most studied is radioactive iodine with a relatively short half-life. Strontium and cesium have been studied. Others may be equally significant but hard to study or pin down. Strontium was incorporated into the dental enamel of childrens' teeth during the time of atmospheric testing. Each test produced a detectable peak.
It is customary for nuclear physicists to speak in terms of half-life. However, when the whole decay pathway for say Plutonium 238 is examined - around 12 radioactive daughter products are produced including Radium and Radon. There is extensive documentation of biological effects of these. Biological effects can be expected from the whole decay pathway. [See Decay Simulation ]
Some Serious Questions:
When it comes to "nuclear demining" - such a task would seem to be impossible. A landmine demining program is daunting enough. What can be done to recover such biologically harmful material from the environment?
How can these materials be detected in living tissues?
How can they be extracted from the living body? - from yourself?
Is there any possibility of remediation for anticipated harmful effects once they are recognized?
Where are the "at risk areas"? - Places where nuclear materials are mined and processed; military sites; storage sites; testing sites; nuclear reactors (80% of Soviet nuclear reactors were built close to geological fault lines); nuclear processing plants.
Should the living oceans of the world be treated like a sewer? Until Man began to interfere - they were teeming with life. Many nations are dumping unwanted hazardous materials in the seas. Is this wise? Nature is highly adept at recycling - what goes down is likely to come up again in the water cycle, or the food cycle though it may take a thousand years. Is it wise to lay up trouble for the future - until a storm stirs up the toxic sediments? Why is there so little information and understanding about occult elements in foodstuffs?
Why are human remains and other species remains not routinely checked or sampled for lifetime total heavy metal burden?
Might there be a quantitative threshold for individuals and for living populations in relation to these matters? - What happens when a threshold is exceeded?
How is it possible to justify the NASA Cassini project to Saturn planned for early October 1997 which will be carrying 33 kg of Pu238 intended for electricity generation but placing at unprecedented risk the integrity of many lives on earth - including inumerable unborn - in the event of an unplanned misadventure.
Does anyone have a clear understanding of the global ramifications of these many difficult problems potentially affecting all species, and all progeny?
Will people of future generations look back on these times with horror for what we did to the bountiful inheritance of Nature? Will the verdict of history be ignorance, willful folly or crime? As these kinds of problems accumulate, how long can we hope that Life on Earth will continue?
1. From At Work in the Fields of the Bomb, Robert del Tredici, Harper and Row, 1987, page 39.
2. Plutonium in the Environment Symposium Report,
Ottawa, July 1994:
http://www.elsevier.nl/estoc/publications/store/3/09698043/SZ955324.shtml
3. Environmental Plutonium in Humans by David M. Taylor (see Plutonium in the Environment)
4. Complimentary material is available at:
http://www.pgs.ca/pages/nlnucleg.htm
rhoffman@animatedsoftware.com