In toxicology, there's a saying that "the dose makes the poison", and anything can be toxic if the dose is big enough. Oxygen is quite poisonous if the partial pressure of oxygen in the gas you're breathing is above 3 atmospheres - only a concern to scuba divers. Water will kill you if you drink enough to drop the concentrations of some ions in your blood too low. There is no doubt that really high levels of radiation are quite good at killing; they use it to kill cancer. There is no doubt that lower levels - to some point - can cause cancers and birth defects. It's lower levels, between background and these toxic levels that are the question.
If you believe no amount is tolerable, you have to ask yourself some tough questions. Start with the fact that some places on earth have naturally occurring radioactivity at much greater than background levels. Why doesn't life die off in these places - or have horrible cancer rates? Colorado, with 15-20% higher natural radiation than surrounding states, has a lower cancer rate than the states with lower radiation. When radioactivity was first discovered, all sorts of claims were made about radiation being good for you. The claims resurface from time to time, here's one from 2002, but these claims get little traction in the general public.
When the reactors at Chernobyl melted down in 1986, and the immediate crisis was over, the governments of Belarus and the Ukraine together created an exclusion zone around the nuclear plant. It has become an oasis of wildlife that is surprising those who go there. In Slate (of all places) we find an article on the place by author Mary Mycio.
The explosion and fire here spewed the equivalent of at least 20 Hiroshima bombs’ worth of radiation, mostly within about 25 miles of the reactor building. The most radioactive isotopes have long since decayed, and rain has washed the rest into the soil and the food chain. Two of the most persistent isotopes are cesium-137, which chemically mimics potassium, and strontium-90, which imitates calcium in living things. As these isotopes have been taken up by plants, animals, fungi, and bacteria, radioactivity is no longer on the zone, but of it.It's a mixture of good and bad news. The area had been mostly devoid of large mammals - deer, moose, wolves, lynx - which had been displaced by the Soviet pine plantations and farms. They returned almost immediately. On the other hand, animals adapted to living off humans - pigeons, rodents - experienced decline. Mycio writes:
This is a unique ecosystem, twice the size of Rhode Island and about evenly divided between Belarus and Ukraine. A generation after most humans abandoned the area, forests and wetlands have consumed once-tended fields, villages, and towns. Only the occasional carcasses of crumbling buildings mutely testify to the former occupants.
Of the dozen moose sightings I’ve had in my lifetime, all were in the exclusion zone, where in the course of many journeys I’ve spent more than a month’s time researching my book Wormwood Forest: A Natural History of Chernobyl. It’s a strange and beautiful place where I’ve spotted wolves in broad daylight; lynx tracks in the snow; and huge herds of boar, roe deer, and elk. I’m still drawn back.To be sure, there were deadly levels of radiation there. A whole forest turned red when the radiation killed the chlorophyll in the plants, taking away the leaves. The Red Forest is still a freakish looking place, but normal, green plants are returning. To be sure, some animals were freakishly mutated - but they either simply died, unable to survive, or were eaten. That phase of the disaster appears to be over. Even animals being found with radiation levels in their tissues far above normal limits appear to be healthy and surviving well in the area.
wolf in a Chernobyl bog)
Many people have heard of the Ukrainian girl who rode her motorcycle through the area many times taking photographs, Kid of Speed There's a thread online that this is a faked story - but even those seem to say that the pictures are real and the places are real, just that she didn't ride her motorcycle. I really don't care if she was in a car, bus, or on a motorcycle. I don't know if it's fake or not.
The conclusion here isn't "Chernobyl Was Good!". It's that, perhaps, an area like this doesn't need to be abandoned for thousands of years. That, perhaps, the environment has a tendency to correct itself like your body's homeostasis systems that keep you normal despite everything that happens in and to you. That, perhaps, the persistent low level radiation leads to some sort of adaptation. I just present it as an interesting read.
That's encouraging. I got rained on from the Chernobyl fallout. It might have made me bald(ing), but why am I fat? Explain THAT, Science!ReplyDelete
I saw the Kid Of Speed articles a long time ago, pretty impressive stuff.
Among the laws of Nature that scientists tend to spurn, because they lack the sort of narrowly focused predictive power that characterizes science, are these:ReplyDelete
1. Life adapts.
2. Life seeks life.
If a planet has some living, reproducing organisms on it somewhere, eventually every distinct environment on that planet will be occupied by living, reproducing things of some variety. That's the way life shuffles. If we need a better demonstration than the Radiodurens bacillus, which lives in the cores of nuclear reactors, I can't imagine what it might be.
I think of it more like a "zeroth law" - an axiom that helps define the ones that come later, the ones that are more testable.Delete
I think the Jurassic Park character Malcolm, the chaostician, said "life will find a way". Not a bad way of putting it.
There are bacteria that inhabit the thermal vents of Yellowstone's geysers, at temperatures approaching 100C. There are organisms along the mid-Atlantic ridge and other extremes of pressure. Radiodurens is another excellent example of an extremophile.
I've recently read that our own bodies contain more bacterial DNA than human by several orders of magnitude. Life is nothing but tenaciously adaptable.
The devastation fron the Mt. St. Helens eruption didn't last nearly as long as scientists predicted it would either.ReplyDelete
Excellent point. I was there ten years ago and that was something they talked about.Delete
If you would like to understand better the biological effects of radiation here is a good reference about Chernobyl. Basically more people die from the fear of radiation than from radiation. I am a former health physicist that studied radiation and health effects.ReplyDelete
Observations on the Chernobyl Disaster and LNT
Locate the BBC documentary, "Nuclear Nightmares," that aired in 2006. It is an examination of Chernobyl after-effects in 2004 through the eyes of one mother accompanied by her 18-year old daughter that was not aborted due to irrational fear of low level radiation. Powerful. An experiment with high background (200 mSv) from Ransar, Iran, and normal background blood samples indicates that a hormetic dose of up to 100 mSv will provide resistance to cancer. When high and low background blood samples were exposed to 1.5 Sv the blood from people living in high background areas had less chromosomal abnormalities than those living in normal background radiation. Radiation stimulates DNA and other cells that protect your body against radiation. This is called radiation hormesis, or, "What doesn't kill you makes you stronger."
Thanks! I ran across that term (radiation hormesis) while putting this article together.Delete
Every person I've ever come across with a background in radiation effects tells me some version of your "Basically more people die from the fear of radiation than from radiation." Coming from a EE/Physics background, I'm naturally inclined to want to see numbers and do the math myself. Off to read more!
Here's an excerpt from a short article I wrote in April 2011 after Fukishima. I can send you the complete article if you wish.ReplyDelete
The human body exhibits properties of a complex adaptive system. An agent (radiation) acts on a complex system (human DNA and cells) and the system in turn responds and becomes more resistant to the same agent and others that can cause injury, disease or early death. The system (our body) adapts and evolves which makes it more resilient to future stressors. This is explained further in The Linear No-Threshold Relationship Is Inconsistent with Radiation Biologic and Experimental Data < http://radiology.rsna.org/content/251/1/13.full >(2009).
Professor Luckey was a prolific researcher in the radiation hormesis field. He re-investigated the data from thousands of experiments done over 80 years. His book, “Radiation Hormesis” (1991), demonstrated hormesis in humans and animals by taking a fresh look at existing data from over 1,000 references. See Luckey's Radiation Hormesis: The Good, the Bad, and the Ugly < http://dose-response.metapress.com/media/h07kwvqxuqde9t6kducy/contributions/8/2/2/2/82225q6w8x050112.pdf > for a 22-page overview of hormesis.
The International Dose-Response Society < http://www.dose-response.org/ >, based at the University of Massachusetts, Amherst, has continued research and study in this area. Nuclear Energy and Health and the Benefits of Low-Dose Radiation Hormesis < http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664640/ >(2009) is an excellent 40-page history of radiation, the LNT theory, hormesis and the need to change radiobiology standards. Overly conservative standards are wasting millions of dollars in unneeded environmental clean-up, but even worse, are unnecessarily alarming people.
The book, Radiation Hormesis and the Linear-No-Threshold Assumption < http://www.springer.com/medicine/radiology/book/978-3-642-03719-1 >(2009), by Dr. Charles Sanders, is a comprehensive review of all facets of radiation hormesis and is highly recommended. Excerpt from the preface to Sander’s work:
"The most dishonest, manipulative research I have ever seen in my nearly 50 years of participation in radiobiological research has been published by radiation epidemiologists who are proponents of the LNT assumption. Their hundreds of publications and involvement in national and international radiation protection agencies have put them in a position of power and control within the research establishment. They have continued the deception in spite of overwhelming published, scientific data that clearly demonstrates how wrong the LNT assumption is. . . .
"The result of this deception is not insignificant: literally millions of lives are less healthy because they have been convinced that living in radiation deficient environments is healthy; lives are lost in not implementing effective low-dose radiation therapy to treat cancer; lives are lost out of fear of diagnostic radiation that saves lives; painful lives of people suffering from chronic inflammatory diseases are not improved by low-dose radiation therapy, which is given without the cost and side-effects of drugs and pain killers. Then there are the annual billions of dollars spent needlessly to protect us from radiation that we need for optimal health. Radiophobia limits the political will of people and governments to promote clean and safe nuclear power in place of traditional highly polluting fossil fuel power sources. Radiophobia prevents the logical and safe burial of nuclear wastes. Radiophobia causes serious psychological effects leading to loss of life (>100,000 abortions and >1,000 suicides attributed to Chernobyl fallout)."
Read the Dr. Sanders book for the best meta-analysis I've read in 20 years. You can find the PDF online by searching appropriately.
Thanks for the info. I should search for Dr. Sanders' book over the weekend, when I have a bit more time.Delete
If you'd like to send the full article, my email address is over there on the right side bar: SiGraybeard at gmail dot com
Decode as it appears.