OT but interesting: a paper on the risks from low-dose radiation

[Andy Champ]

Both these groups have had discussions about nuclear power, wind power, and the dangers and uselessness of them. I came across this:

It suggests that the linear no threshold model is indeed wrong. But much to my surprise, it seems low doses are _less_ safe pro rata than higher ones. So if a given dose give you a 1:100 chance of getting cancer, 1/1000th of the dose doesn't give you a 1:100,000 chance (as linear no threshold suggests) nor a zero risk (as has been suggested from examining records from places like Dartmoor) but a higher risk, perhaps 1:50,000.

Probably still not enough to matter, but still interesting. And I still think wind farms are useless!

Andy

[newshound]

That's not my reading from the abstract of the article, isn't it saying that a given dose received in a short time is less damaging than the same dose over a longer time?

If that's correct, it does mean that sums based on the Atom Bomb data are wrong, so certainly an interesting point for professional health physicists.

That's actually the other way round to what happens with radiation damage to simple polymers, where a high dose rate for a short time is more damaging than the same dose received over a longer time at a lower rate.

However it doesn't change the arguments over the real risks of nuclear power. Natural background is far higher than what is normally received from power stations (coal or nuclear!). You can't detect a "background" effect between, say, Aberdeen or Dartmoor and Manchester or Cannock Chase. So you certainly can't detect any effect associated with nuclear power (except in accidents which give very large doses). At the end of the day, science is based on evidence, not on predictions from models.

[The Natural Philosopher]

Its all a lot more complicated than pure dose. getting a year's dose in a day is far more dangerous than doubling the overall dose.

likewise getting all the dose in one PLACE in your body is more dangerous than being bathed gently in radiation over the whole body.

Additionally the bioactivity (or not) of the radionuclide itself counts

- that's why iodine is nasty - goes straight to one place - the thyroid. And stays there.

Finally the emission type makes a huge difference. Gamma burns, but neutrons or other nuclei can smash DNA to bits.

the LNR is a very very SAFE model but its not a true one - not at all.

Well they are.

[The Natural Philosopher]

That seems to be the case with tissue as well. Peak intensity is more important than overall dose.

Its been suggested that up to a limit, like digital radio transmission, 'parity errors' can be 'corrected' but beyond that level the damage is uncorrectable: Mostly the tissue dies but sometimes it mutates.

cancer rates are significantly higher on dartmoor for example.

So you certainly can't detect any effect associated with nuclear

That is true of te power staions, there may be some effects associated with reprocessing where standards are lower and there is much more handling and of course in an acident scenraio.

However its unlikely ANYONE will die from Fukushima which is the second worst nuclear accident there has ever been in terms of total release.

[The Natural Philosopher]

Oh you should take a look at tehe web site that PRODUCED this paper.

draw your own conclusions from the way material is presented, as to which axe they really want to grind.

[The Natural Philosopher]

that is

The Bulletin of the Atomic Scientists informs the public about threats to the survival and development of humanity from nuclear weapons, climate change, and emerging technologies in the life sciences. Through an award-winning magazine, our online presence, and the Doomsday Clock, we reach policy leaders and audiences around the world with information and analysis about efforts to address the dangers and prevent catastrophe. With fellowships for students and awards to young journalists, we help educate the next generation. History

The Bulletin of the Atomic Scientists was established in 1945 by scientists, engineers, and other experts who had created the atomic bomb as part of the Manhattan Project. They knew about the horrible effects of these new weapons and devoted themselves to warning the public about the consequences of using them. Those early scientists also worried about military secrecy, fearing that leaders might draw their countries into increasingly dangerous nuclear confrontations without the full consent of their citizens.

[Brian Gaff]

hmm, well, humans and other organisms have evolved on this planet with does have and has had radiation. I cannot help but suspect that not only the problems of free oxygen were a problem, but also radiation. Hence the ability to breed and repair a lot of the genetic damage.

The very random damage high energy particles etc can cause to cells and genes has to mean that no way can you actually quantify the risk. It all depends on random events and how the damage affects an organism really. Brian

[Steve Thackery]

How very bizarre. Bizarre because only a couple of years ago I saw a programme on TV (Horizon, maybe? - some other reasonably respected science programme anyway) where it also said the "linear no threshold" model is wrong, but in exactly the opposite way!

In other words, below a certain threshold the cancer risk drops straight down to zero.

I remember one scientist making the memorable statement "low-level radiation is a piss-poor carcinogen".

So there you go; for every expert there's an equal and opposite expert.

[Steve Thackery]

But surely you can quantify it statistically? With a large enough sample size?

[Tim Streater]

Indeed. Oxygen can be a very dangerous gas; try breathing pure oxygen at atmospheric pressure for very long and say goodbye to your lungs. When life first started producing oxygen, there was no ozone layer (yet) and so the sun's UV produced lots of free radicals by splitting water molecules [1]. Life had to evolve ways of dealing with that, which of course it did. Vitamin C is one such.

[1] Most life contains a lot of water (e.g. we're about 75%). Energetic particles, such as cosmic rays, can zip right through you without encountering much of anything but water molecules, which they break up, leaving a trail of free radicals behind. It is these, rather than the radiation itself, which do the damage inside cells.

[Tim Streater]

A cell that's damaged starts emitting certain chemicals, which are noticed by (I think) immune cells. These then inject into the damaged cell a chemical which triggers suicide mechanisms in the damaged cell, which then breaks itself down in a orderly way. IIRC, cancer cells have ways to disable that suicide mechanism.

[The Natural Philosopher]

The site in question is dedicated to publishing 'the truth (sic!) about the dangers of nuclear power' its one of the very old cold war organisations that presumably were sponsored by the Russians - and probably still are. They have the gas and the nuclear technology.

The research is almost certainly nothing of the sort, but merely bending statistics to get the answer they want. "All nuclear radiation is dangerous".

This report is not from experts. Its from nut jobs.

[Peter Duncanson]

That is probably true in terms of death from radiation exposure, although the people who worked in the power stations to get things back under control after the tsunami might be at risk.[1]

However, there were deaths caused indirectly by the Fukushima power station failures. I seem to recall a figure of 100 or more. These were deaths during the evacuation of the area near the power stations. The evacuation zone includes towns with people of all ages and states of health. There were hospital patients who under normal cicumstances would be considered totally unfit to be moved because of the immediate risk to their lives. There were patients on kidney dialysis, dozens I think, who had to be moved to other hospitals, in some cases hundreds of miles away. Some hospitals could take extra patients others could not.

[1] Older workers volunteered to work in the damaged power stations in place of younger ones on the declared basis that they had less of their lives left and that even if they died earlier than normal they would still have lived full lives.

[Tim Streater]

These were indirectly caused by the tsunami. If Fukushima had been a plant producing interesting chemicals, the surrounding area might still have had to have been evacuated, due to the toxic nature of the chemicals released. In either case, you could then criticise the placement of the plant, but it would have nothing to do per se with what the plant was doing (energy production from nuclear or chemicals production from oil-based feedstock).

[Peter Duncanson]

Is it not reasoinable to consider secondary, indirect, effects.

[newshound]

It's more complicated than that, too. A high local dose may give you a burn, without increasing cancer risk. A whole body dose of ~ 5 Sv is very bad for you because it knocks out *all* the bone marrow and hence the immune system. But you will probably survive 20 Sv to a leg (assuming a leg is about a quarter of your body weight).

[Andy Champ]

Perhaps the main point is that at the low doses in question the risk is almost unmeasurable anyway. Nevertheless I felt the data should be available to the people here.

Andy

[Tim Streater]

But those were just what you were considering. You were looking specifically at how some 100 people might have died, who wouldn't have died but for the tsunami. The *path* to their death is interesting but not particularly relevant to anything, especially when you pick those

100 out without considering appropriate paths for the other 19,900 who also died.

[The Natural Philosopher]

Unlikley. The were kept within single dose limits that are essentially safe.

No, there were not.

These were

But no one died from that.

[The Natural Philosopher]

Not in the context of nuclear power versus some other form of power, no. Indirect effects could for example have been people dying due to lack of power from ANY powerstation that got knocked out.