John Cuthber

Perhaps more useful to know is the variation of the solubility with temperature. At 0 C the solubilities are 37.5 and 79 g/100 ml At 100C they are 39.12 and 230 g/100 ml

"Something doesn't feel right here. Removing 1.3 pounds of air from 128 cubic feet (10+ pounds) results in a half a ton of pressure? " Whatever it "feels like", you saw me do the maths and the answer is 4 tons not half a ton. Air pressure is a lot bigger than most people realise. The force it exerts on a typical door is about 15 tons Here's a slightly naff demonstration. http://youtube.com/watch?v=rX52TsJCuKA

"Can you provide a citation for this? Everything I've seen so far has referenced background radiation levels, not dosage to lung tissue." No, but I can repeat my observation that what's in the background will get into the lungs so some extent and, whatever that extent might be, there's no clear reason why it should be different for Po derived from smoke or Po from background radon. "Actually what I was saying was that mainstream cigarette smoke contains both soluble and insoluble Po210 compounds. The soluble compounds are cleared by natural process. The insoluble ones are deposited at bronchial bifurcations and are not easily cleared by natural processes." What evidence can you offer that Po from background radon doesn't also form both soluble and insoluble compounds? Without that, I'm inclined to say they are pretty much the same thing and, therfore, I blame most of the damage on the thing that produces most of the exposure. I wonder if you can find any recent paper that supports Martell's ideas? I seem to have found a few that say such support is lacking. If there's no such support then he's a lone voice- even if it's published in Nature a single paper isn't proof. I realise he may have published shedsfull of papers based on this hypothesis- what I'd like to see is evidence of anyone outside his research group agreeing with him. There certainly seems to be evidence that the EPA disagree or they would be lobbying for the power to do something about it. I think it's fair to say that, like most groups, the EPA would like more authority and a bigger budget- this idea would offer them that so you have to ask why they haven't taken it up (I realise you have written to ask them exactly that but until you get a reply it's still an interesting question). Why do you think the EPA is not angling for a research budget for this problem?

Would reletivity give rise to an increase in mass? It would certainly have a lot of energy (though I think the estimate of a gram is a few orders of magnitude worth of optimistic)

Thanks for pointing out that I wasn't lying and that the people who make those HPLC columns are not idiots.

"But there are 8 surfaces at 4 square feet each, not one at 32 square feet.." OK so you have lots of 4 by 4 squares carrying half a ton, each supported by 4 thin balsa struts 4 feet long. Here's the formula I think you need to look at before bothering with CAD/CAM http://en.wikipedia.org/wiki/Buckling I haven't done the maths (because I don't have the exact dimensions of the struts and the equation raises that data to the 4th power so there's not a lot of point me guessing it from the picture). Or you could take the empirical aproach. Stand one of the struts vertically and put a 275 pound weight on top then see what happens.

Lead and polonium are both metals. They are not volatile. I don't think its naive to expect the lungs to do a good job of trapping them. I also think the filter in a cigarette, or, in the case on unfiltered ones, the "dog end" would do a fair job of trapping the stuff. As I have pointed out, the inhaled dose of these same nuclei from background radiation is something like a hundred times bigger than that from smoke (and the ratio is bigger yet idf the remains of the cigarette retain any of the Po that it originally held). You are hypothesising that somehow the body can exhale this metal when it's not from smoking but it traps it when you are talking about smoke. That, to me, seems naive. If I'm naive in believing this then at least I can take comfort from the fact that a major government body suffers from the same naivete. It's interesting that you accuse me of refering only to radiation levels rather than radiation dose. I explicitly mentioned dose and pointed out that the dose levels quoted (of the order of hundreds of Grays) would be well into the realms of radiation sickness from one cigarette. As I said, it depends on what mass you chose to divide by. If you calculated the dose for the Bi atom itself as it disintegrates, the dose would be phenomenal, but meaningless. (BTW, if you don't think that is "pointing out a flaw in the Martell paper" what, exactly, do you want?) Radiation dose only exists because of radiation levels. It doesn't make sense to only try to talk about one. All things being equal the higher the level the higher the dose. Some radioisotopes like radiokrypton are not particularly hazardous because the stuff is exhaled quickly. On the other hand, things like strontium 90 are particularly nasty since they are readily absorbed by the body and poorly excreted. Exposure to the same activity of these two materials would not give the same absorbed dose because one leaves and the other stays. OK, but what we are comparing is inhaled Po and Pb radioisotopes from radon daughters versus exactly the same stuff from the same source. The difference being that, in one case, there's about a hundred times more of it. Now to me that's pretty clear grounds to supose the absorbed dose 1 will be bigger for the bigger exposure and 2 will be in the lungs in both cases. I accept that I havent provided a peer reviewed refutation of this paper but I did quote another paper as saying "The Martelll "Hot Particle Theory" has been addressed in the past and has apparently lost popularity in the scientific community ". Given that you cited that paper in the first place, I presume you agree with it. How about, from this http://www.fortfreedom.org/p22.htm This quote " a relatively less publicized attack on the conventional approach to evaluating Pu toxicity is the ``warm-particle'' theory of Edward Martell. He hypothesizes that natural radiation is one of the principal causes of lung cancer, but this idea has not been accepted by the cancer research community."

G block elements anyone? http://en.wikipedia.org/wiki/G-block

Riogho's idea is good. "I say we accelerate the space station so that the forces acting on our bodies are equal to 1g. I win. " But he only wins if he can think of a way to supply the power required to maintain the acceleration.

It's probably a cockup, but there are times when, in calculating entropy or statistics and such when you really need to calculate some odd looking numbers. Stirling's aproximation gets used quite a bit in statistical mechanics. http://en.wikipedia.org/wiki/Stirling's_approximation which lets you calculate the log of factorials that won't fit in the calculator.

"why do you oppose the EPA having authority to regulate it?" According to wiki "The U.S. Environmental Protection Agency (EPA or sometimes USEPA) is an agency of the federal government of the United States charged with protecting human health and with safeguarding the natural environment: air, water, and land. " They have responsibility to regulate things that affect the health and environment- Po in smoke doesn't affect them to any meaningfull extent. They also have better things to do. It's the nicotine in cigarettes that's addictive. Removing it would get most people to stop smoking. This would reduce the net harm done. Also, while nicotine isn't carcinogenic, it is the most likely candidate for the detrimental effect smoking has on the heart. Those effects are within EPA's remit, the trace of Po isn't. There's almost certainly uranium in cigs too, why not worry about that? Come to that, there will be plutonium from nuclear fallout. Do you think it's worth removing that? This is a reply to a post in another thread. The OP is trying to keep the science of Po toxicity separate from the legal/ political issues of the EPAs regulatory authority. As I said, the EPA's role is clear - they regulate risks to people and the enevironment. Since the exposure to Po from cigarettes is not a major part of the hazard from smoking (in fact I don't think it's even a measurable part), they don't have any rules to deal with Po in smoking materials. That's consistent with their reply that "existing laws to not authorize EPA or other federal agencies to regulate this source of radiation." The other part of the reason is that its NORM and you can't legislate against rocks. There's nothing in the reply the EPA sent you that supports the idea that the Po content of tobbaco has any significant effect on health. You certainly can't say that it agrees with Martell's paper which talks about putative damage to the lungs. The EPA's response simply tells you what everyone knows- the stuff is from the phosphate rock used to make fertiliser. The EPA are, as you say, fully aware of the assertion that Po is harmful. Their business is to control harm, yet they are not seeking legal authority to regulate the Po in cigs. I think that's because, like me (but unlike Martell), they don't think it's a significant cause of harm.

This is turning into a messy crossed thread. I will reply in the other thread but, just to clarify things for anyone reading this thread, here's what I understand they told you "Thank you for your inquiry. The simple answer to your question is that existing laws to not authorize EPA or other federal agencies to regulate this source of radiation. The primary issue is that it comes from a naturally occurring radionuclide. The radiation in tobacco comes from phosphate fertilizer, which is made from naturally occurring phosphate ore. Radium is commonly found in the rocks that contain phosphate ore and is the origin of the radiation in fertilizer. When phosphate fertilizers are used on tobacco, radon, a colorless, odorless, radioactive gas, which is a decay product of radium, rises from the soil and deposits its decay products on the underside of tobacco leaves. Tobacco leaves are sticky so the radionuclides (notably lead-210) stick and decay to polonium-210, which is subsequently inhaled by the smoker. " Is that the whole of what they said (apart, of course, from dates names addresses and such that don't matter and you wouldn't want published)?

I'm not sure that the two are separate. The reason the EPA don't regulate Po in cigs is based squarely on the science- there's no meaningful risk to health or the environment.

I take it this thing was 4 by 4 by 8 feet. That's pretty big. You want to take about 13%v of the air out of it. That will give a differential pressure of roughly 13% of an atmosphere. 1 atmosphere is about 15 pounds to the square inch so you are after 1.9 PSI difference in pressure. That's 275 ponds to the square foot so for the 4 by 8 foot face you are talking about a load of roughly 4 tons. Challenging. OTOH, if you can heat it to 60C...

Much better to do this with adequate ventilation than with a gas mask (particularly one from ebay).

I understand that a major part of the problem with zero gravity is that it affects (or rather, doesn't affect) the balance organs in the inner ear. Together with the problems give above I think it's a non starter.

Interesting. If it's real then it's suprising that it hasn't been spotted before. Anyway, it shouldn't be difficult for someone to confirm it.

No, because Al reacts with water to give the oxide and hydrogen.

I probably got the figure of 20 Bq from th enet- most likely the same place I got the lead cadmium etc figures from. Since, in both cases, we are talking about inhaled Po and the lungs are very good at trapping stuff I'd say that the roughly a hundred times more Po from background leads to roughly a hundred times more exposure in the lungs. The figure of 80 -100 Rad is misleading- if you take a small enough volume the local dose will always look huge. According to this http://en.wikipedia.org/wiki/Gray_(unit) a dose roughly 20 times bigger than that ought to kill you. 20 cigarettes doesn't cause death by radiation sickness "A whole-body dose of 10-20 grays of high-energy radiation, delivered at one time, can be fatal to humans" "One gray is equivalent to 100 rad." I can't remember now where I found the figure of 20Bq-it has been 9 months or so. Why the necromancy?

Well, obviously we don't know what particular 3 ring compound you mean but if it happened to behave anything like this one http://en.wikipedia.org/wiki/Thc then you could trap it on activated charcoal or destroy it with bleach or some other strong oxidant. The percarbonate based "eco friendly" bleaches might oxidise the phenolic part of that structure to a quinone which would certainly alter the smell. Oxidative cleavage of the double bond would lead to chamicals which would, in turn be oxidised to form acids which would be trapped by the alkaline material. Actually, most compounds that big are not very volatile so they are not the actual cause of the smell. Of course, if the molecule is something else but similar that might be trapped in the same way. If it's something else entirely perhaps you might be able to tell us more about it so we can help.

"Do you think, just as a matter of principle, that the EPA should have the power to regulate them?" No, because they can't legislate against rocks. People die from smoking but it has very little to do with the polonium content and a lot to do with things like nitrosamines and PAHs. If it made sense to ban Po in cigarettes it would make a lot more sense to ban nicotine. It's not going to happen. This has been debated before. The additional 20 or so Bq of Po that a smoker picks up isn't going to make any difference compared to the backgroung levels of about 1500 Bq from natural radon. http://www.scienceforums.net/forum/showthread.php?t=27298

You already have the distribution. Unfortunately for you it might not fit very well to any of the "usual" distruibutions. The data might not be normally distributed, they might not fit a laplace or Weibul distribution either.

IIRC cherry laurel leaves have been used in the past to generate enough HCN to kill bugs for this sort of thing. http://en.wikipedia.org/wiki/Cherry_laurel I guess there are similar cyanogenic plants where you are.

"is a nuclear reaction reversible?" I believe so, but the temperatures requierd are a bit awkward to deal with. Do you have a tame supernova in your lab?

You need to use the right metal for the glass too. If not then differential expansion on heating will crack the joint when it cools. There's an alloy caled kovar that is used for this trick for borosilicate glass IIRC platinum works for some varieties of glass too. (There are other ways too but this problem is an art in it's own right). A cop-out way to do it is to use a glass seal that someone else has made, like an old TV tube or light bulb. You still have to match the expansion coefficients though.