Gokul43201 said:
Might be a comprehension issue on my part, but how does "Mostly no" answer the question "does 'those' refer to cancer?"
So, really all we can say is that the numbers derived from the causes that are well understood provide a lower bound on the deaths, and the error bar in the location of the upper bounds increases with how poorly the other causes are quantified.
It's two different things to say we know the upper bound is very likely below X, and to say that we have no good understanding of the upper bound, so let's stick with the lower bound estimates.
We have no good understanding of the upper bound even with decades of experience, and that upper bound is a factor of so many elements that are not understood that to discuss it is absurd. So yes, we discuss, not the LOWER bound, but the only number that can confidently be discussed at all. After all, someone who receives a nearly fatal dose of radiation is going to be undergoing full body scans on a regular basis for the rest of their life. They may develop cancer, but who's to say it will kill them? Even more, because of the nature of the enormous disparity in reactions to an "instant" vs. fractionated dose, you can't even tally the numbers for someone and say, "ahhh, their risk increases by n".
I want to emphasize that when we're talking about near-lethal exposures (4-5.5 Sv) from a single incident, that lower bound seems to be VERY near the crude estimates of an upper bound. The one thing you can say for certain is that if you get 6+ Sieverts in a single blow, you're almost certainly going to die within a month, but if you take that and make it 1 Sv per year, over 6 years, you almost certainly will NOT die unless you develop aplastic anemia, cancer, etc. Radiation just isn't simple... it'd be like you track everyone who survives a bullet wound and tried to factor in how it contributed to their death after 10, 20, 30... years. It's just... different... I don't know any other way to put it, and that assumes that you account for the REAL total absorbed dose to given regions of the body! Sorry, there just haven't been that many people who've been exposed to just the right amount of radiation to NEARLY die, but pull through. Then again, we have victims of Dioxin poisoning who you'd expect would be dead in a few years, but last decades or longer.
My point isn't that radiation won't drastically increase your risk of later ailments, but that anyone claiming to draw a hard number from current medical science is LYING.
As for mostly no, yes, I was referring to cancer. There are coal fired plants in the USA, and their effects, and then there's burning of coal in homes in rural China, where you have healthy non-smokers with a ridiculously high rate of lung cancer. It's a much simpler issue, but even it is pretty broad. For instance, the burning of Bunker Fuel for shipping is estimated to contribute to 80,000 deaths worldwide, but this isn't a body count, it's a statistical model. When you get into the realm of radiation exposure, you can't just sample the liver post-mortem and say, "ah ha, this man was a mess".
So, JarednJames that's exactly what I'm saying; numbers beyond what can be attributed to acute exposure are guesswork. This goes to your last post... you see, some people believe that minimal radiation exposure is in the same linear relationship with mortality as larger doses. OTHERS believe that small doses of radiation result in hormesis, which actually STRENGTHENS someone against further exposure. Thus far, the debate goes on, so no, there's no lower limit to damage, but there is an index of observable symptoms vs. acute exposure.
Personally, I don't buy the hormesis argument and would err on the side of caution along with regulatory agencies:
http://en.wikipedia.org/wiki/Radiation_hormesis
For a very rough guide, Wiki strikes again:
http://en.wikipedia.org/wiki/Radiation_poisoning
I've researched this subject far beyond anything wiki for years, and nothing I've ever read leads me to understand how one can arrive at such a vast number. To do so would require a MASSIVE longitudinal study the likes of which does not exist for radiation exposure of this type.
I will add my 2 cents however, and that's simply that Vanadium is almost certainly within an acceptable margin of error here, because I find it hard to believe that the TOTAL radiation output is absorbed evenly and completely by PEOPLE! If you empty a machinegun into a group of soldiers, you miss some (which we equate to a low dose), you hit others wounding them (medium dose), you kill others with a single shot (6 Sv or more), but you ALSO riddle some with maaaaaany bullets, and some end in the dirt or trees. In the case of ionizing radiation, the same is true, but the variables are far greater. I find it absurd to assume that the equation is a clean 600K/6 = Max possible in a real world situation, because that's 100% efficiency... with 50% dead without medical care, and most if not all dead without.
In reality, if that output is accurate then some is lost in critters, trees, rocks, dirt, air (poor shielding, but there's a lot of it) and so forth. Some people probably absorbed more than 6 Sv, and others less. Vanadium gives a relatively clean maximum death count, but for the purposes of bringing this closer to reality, I suspect the deaths would be far less than 100,000 attributable, not more.
That finishes it with Gokul's point about lower and upper bounds... this is a real, but purely academic "upper bound", constructed as though each person were given 6 Sv lying on a table, then moving on to make way for the next victim. In life, this is not the case, so 100,000 is more of an UPPER bound than a lower bound in my opinion, and nearly 1 million is not only impossible, but genuinely laughable. If that were the true state of affairs, pilots and frequent fliers would all be cancer riddled husks, as would many recipients of radiation therapy, etc... etc... I don't buy it. I don't even understand HOW that kind of number is arrived at... not at all.
