The Five Stages of Collapse

[RenewableCandy]

Chernobyl released Caesium 137 with a half life of 30 years, but the contamination did not reduce as expected, so half life may not be the only consideration.

http://www.wired.com/wiredscience/2009/ ... obyl-soil/

what does "the contamination did not reduce as expected" mean?

This bit I suppose:

Cesium 137′s half-life (...) is 30 years. In addition to that, cesium-137’s total ecological half-life — the time for half the cesium to disappear from the local environment through processes such as migration, weathering, and removal by organisms is also typically 30 years or less, but the amount of cesium in soil near Chernobyl isn’t decreasing nearly that fast. And scientists don’t know why.

[biffvernon]

It lasted longer in Cumbria and North Wales that it was supposed to too.

[Little John]

Chernobyl released Caesium 137 with a half life of 30 years, but the contamination did not reduce as expected, so half life may not be the only consideration.

http://www.wired.com/wiredscience/2009/ ... obyl-soil/

what does "the contamination did not reduce as expected" mean?

This bit I suppose:

Cesium 137′s half-life (...) is 30 years. In addition to that, cesium-137’s total ecological half-life — the time for half the cesium to disappear from the local environment through processes such as migration, weathering, and removal by organisms is also typically 30 years or less, but the amount of caesium in soil near Chernobyl isn’t decreasing nearly that fast. And scientists don’t know why.

I read that bit, but it wasn't clear. Presumably, the more of it that remains in the environment, the higher the probability of being exposed to it in any given location, irrespective of it's radioactivity levels . In which case, I want to know precisely how much more is being left in the environment than was originally thought. The article does not make this clear at all.

In other words, is the worst problem with this material it's radioactivity levels or simply the probability of being exposed to it. If, For example the probability of being exposed to it was very low to start with, then if that probability increases by a certain amount (due to the slow rate of removal), this may be of little concern. On the other hand, it may be of great concern. But, nothing in that article makes that clear.

[woodburner]

I want to know precisely ........... .

Do some leg work

[jonny2mad]

I would think its not just natural ability to cope with radiation its numbers in the population and birth rate .
What I mean by that is if you have two tribes one full of gloom and not producing enough kids to replace themselves, and another tribe having ten kids just by pure numbers the second tribe is likely to have more children with the ability to better deal with radiation.

[Little John]

I want to know precisely ........... .

Do some leg work

The question I was asking was related to the specific dispersal and accumulation rates in this particular case as reported as they related to the veracity of the implication that this accumulation represented a significantly higher risk to people than was the previously thought to be the case. That may or may not be the case. However, whether it is or not is entirely dependant on the objective initial and later re-calculated amounts in the environment read in conjunction with cancer rates and nothing in the piece allows that judgement to be made. Furthermore, nothing in the subsequent link you have given allows it to be made either. It simply goes into greater detail about the rate of physical clearance from the environment. But does not indicate how this has affected cancer rates which is, of course, what this is all about, right? Where is does at least touch on how this may increase actual risk to humans, it actually states that the risk is minimal. The single example given being hill walkers. In what way does this paper you have linked to any further support the implication that the the risk to humans is significantly elevated due to slower clearance from the environment that was previously thought to be the case? Of, if you are not trying to imply the above, then of what relevance is your mentioning of it.

You are aware, are you not, apart from the few unfortunate individuals who died as a direct result of working on the reactor and immediate vicinity of it in the period immediately following the accident, the overall rates of cancer in Europe have not increased in any significant amounts and the rates of death by cancer (or any other type of death that may be attributable to the Chernobyl accident) have not risen over and above background, pre-accident, levels even to the point where they could be distinguished from statistical noise? That's a convoluted way of saying that the death by cancer rates have, for all practical purposes, not risen at all, by the way.

[emordnilap]

Actually, having thought about this for a while, I think he's missed something important.

I believe he's right that we are going to end up with multiple nuclear disasters on the scale of Fukushima, due to other natural disasters, rising sea levels or simply a society so broken-down that nobody ends up in charge of "safe decommissioning." So let's imagine we've got a world in 40 years time where there is an extremely high level of background radioactivity in the environment. Orlov sees that as the end - that the level of mutations would be so great that humanity would die out because nobody would survive to reproduce. I think he's wrong.

Studies in the disaster zone at Chernobyl have made very clear that the capacity to protect from or cope with environmental radiation causing genetic damage is itself a heritable trait: some species were far more vulnerable than others to mutations, and some individuals were more vulnerable than others. This is not surprising. DNA has always been vulnerable to damage caused by radiation and other things, and as a result there are quite a lot of complicated molecular mechanisms for detecting and fixing it when something goes wrong. If it weren't for these mechanisms, DNA-based life would never have lasted very long.

Given that there will be a radically-elevated level of mutations, and that there are more than 7 billion humans, the most likely outcome of the scenario in question is that a tiny number of those mutations will actually help to improve those mechanisms. There would be massive selective pressure on the human genome in favour of those individuals with the best radiation-defence systems, and especially those who have mutations which enhance those systems. In other words, some humans would probably survive, but which ones would end up depending almost entirely on this one trait, and all the other traits, from intelligence to disease-resistance to culture, would be totally irrelevant. It would be a genetic lottery, apart from the human race which emerges from the other end of the process would be highly radiation-proofed compared to us.

This would set the scene for further evolutionary changes down the line. Eventually the die-off would slow down and the human population would start to grow again, but life would still be very tough and a more general "survival of the fittest" would kick in again, although it is not clear what "fittest" means here.

Yeah, good point. Post it on his blog, he'll probably respond.