OT: Heart warming

Litvinenko didn't die from heavy metal poisoning, he died from the alpha dose from the polonium.

So what? he got a *massive* ingested dose of a long lived and very nasty isotope. He died in weeks - that probably a 200mSv dose or higher .

Nothing like a very low inhaled dose of a radioactive gas. That could be exhaled if it didn't turn to lead. That ends up in a cancer 20 years later.

The reality is that low doses of radon do not kill half as well as the heavy metals they decay into that are stuck in the lungs for good.

Try not to think like an ArtStudent?...

What do you think happens to the radon? Its gone within days.

We know from studies that cumulative dose is not the issue with low level radioactivity, it is the peak dose.. But we also know that chronic exposure to heavy metals is absolutely carcinogenic.

In short what is hanging around in the lungs is lead 210, and that will build up, and, in the case of smokers, will not be coughed out due to cilia damage. The amount of lead 210 will massively exceed the amount of any of the daughter products that precede it.

And further radioactive decay in fact turns that to lead 206, which is the final stable end product.

The point is that the radioactivity is transient, but the lead is permanent.

I don't doubt that uranium miners and the like inhale dust that does them no good at all, what the balance is between pneumoconiosis and heavy metal poisoning, I have no idea. The fact remains that if you breath radon for long periods, any atoms that decay while it is in your lungs leave polonium and other radioactive isotopes that then continue to irradiate you. While the LNT hypothesis is undoubtedly conservative, radiation damage is still cumulative, and you can acquire significant doses from non-toxic nanogram quantities of material.

The toxicity level of lead (in blood, where it is more dangerous) is something like 0.1 ppm. Lung air capacity is about 6 litres, say the total volume including tissue is 10 litres. Let's say 5kg, so 50mg of lead might be potentially toxic in the lungs.

Wikipedia thinks Litvinenko received about 10 micrograms of Po, which is

Try doing sums instead of making ad hominem remarks.

He snipped this one

Yes, because he ingested it. Your skin or a sheet of paper will stop alphas.

They're not fission products; this is radioactive decay which is not the same thing.

If you inhale radon, you end up with polonium in the lungs.

Yes but he was fed polonium, not radon.

What has cancer got to do with lead poisoning?

Totally irrelevant, we are not talking about lead poisoning, but lead as a carcinogen

Precisely, so completely irrelevant to long term low level polonium exposure. But as you would know if you had bothered to research it, polonium has a very short half life, Its gone very quickly and what is left is lead.

As I say, try not to think like an ArtStudent?...

...and try doing sums instead of thinking like an ArtStudent?..

The point is that you are entirely wrong.

Such radioactivity as exists in radon is far too low - compared with other sources of radioactivity, to match the uptick in cancer associated with long term exposure in conjunction with smoking.

The data is clear. Non smokers show a moderate increase in lung cancer, smokers show a significant increase in lung cancer.

Why is that?

We know that chronic low level radiation does not, after all, cause cancer, so its not the radiation.

If we use our brains, assuming we have any, its clear that the half life of radon is too short to cause damage years alter. Damage there and then perhaps.

What happens, and its established science, is that the radon with a half life of 3.8 days, is completely gone in under a month.

The polonium it tuns into is gone within half an hour.

Then its lead bismuth and polonium again for 10 microseconds.

So very rapid.

What we are left with after a month is nothing except lead 210, which has a half life of 22 years. and is therefore only very very weakly radioactive.

So logically what is in the lungs of people who are chronically exposed to radon gas, is deposits of lead 210 mostly.

Why does this affect smokers so badly? because smokers have damaged lungs and cannot cough up any *solids* they inhale as well as non smokers.

So you see that polonium is a total red herring as is radon itself. You end up breathing radon out if its still radon. the point is that it very quickly isn't radon. Or polonium Its a low level radioactive isotope of lead which slowly turns via a couple of short and medium lived isotopes, into stable lead.

The thing is that the doses are never high enough to cause radiation poisoning,so any comparison with Litvinenko, who did is simply meaningless.

you claimed "Wikipedia thinks Litvinenko received about 10 micrograms of Po, which is 200 times the median lethal dose."

I would say that is probably entirely correct, but a complete red herring, because no one on Dartmoor ends up with anything like that much highly radioactive polonium in their lungs,

We know from research carried out by Wade Allison that long term low level radiation needs to be above a certain value to cause cancer, and needs to be above a much higher level to cause radiation poisoning.

The data from Hiroshima et all conform this - most died from burns or blast, a small percentage who survived that died within months, like Litvinenko, from acute radiation sickness. As did around 50 firefighters at Chernobyl.

A far smaller percentage contracted cancer in the next few months, but almost no one - despite it never being decontaminated, died at Hiroshima or Nagasaki from more than normal rates of cancer.

The fact that in your ignorance you are confusing death from radiation poisoning with death from radiation induced cancer and death from heavy metal induced cancers is regrettable I suppose to you they are all one and the same.

Art Student?...

Heavy metals in the lungs of smokers who cant cough it up, fits exactly as a long term exposure to carcinogens, not a short term exposure to high radiation levels, which is what causes cancer from radiation.

Look it all up. Daughter products of radon will tell you what radon actually becomes and how quickly Any paper on lung damage from smoking will tell you that inability to cough and death of the cilia are characteristic. And account for susceptibility to infection that smokers have. The data from Hiroshima, Nagasaki, and Chernobyl are all in the public domain, and all refute the LNT model of chronic radiation exposure and confirm Wade Allison's research into cell mutation. Low level radiation doesn't cause cancer. It needs to be intense enough to modify both the two strands of DNA, identically, in the lifetime of a cell, or the cell just dies. That's the band where it causes cancers. If the radiation is strong enough to destroy cells, rather than mutate them then that is radiation posioning, and is a different mechanism.

Inhaled radon isn't radioactive enough at the levels it is at naturally to cause cancers. And if it was, it would affect non smokers equally. What it turns into, rapidly are a very long lived isotope of lead, and a reasonably long lived isotope of polonium, and then a fully stable isotope of lead.

None of the radiation involved is enough to cause radiation sickness a la Litivenko. Comparions there are meaningless art student hand waving word association - "radon decays to polonium - litivenko died of polonium radiation sickness..has to be the same thing'

My god, its pathetic

None is actually high enough to cause cancer either, And that is a puzzle, because people - especially smokers - do die of lung cancer on dartmoor, significantly enough to presume a cause effect relationship.

But then we know that lead and the smaller quantities of intermediate polonium are in fact carcinogens in their own right.

If you look at what polonium does via its radioactivity, what you do not see is lung cancer.

It gets into the rest of the body and wreaks havoc everywhere. Lead however...

"Lead exposure has been associated with increased risk of lung, stomach, and urinary-bladder cancer in diverse human populations. The strongest epidemiological evidence is for lung and stomach cancer, which are consistently but weakly associated with occupations and industries entailing lead exposure. Lead is classified as Group 2B carcinogen by the IARC, meaning it is probably carcinogenic to humans."

The conclusion is inescapable, low level radon itself is harmless as it quickly decays to lead 210, which has a 22 year half life. That in turn decays to an isotope with a 5 month half life - polonium

There is clear evidence that high levels of polonium cause radiation sickness, there is no evidence whatsoever that polonium *as polonium* causes lung cancer. Since it all decays into lead in time, the fact of inhalation of polonium in cigarette smoke or via radon, being *associated* with lung cancer is no prof that it is in the end the polonium causing it and specially not through radiological induced mutation.

Lets look at some data on polonium

The alpha particles emitted by 210Po only travel a very short distance in the air (no more than a few centimeters). This radionuclide therefore only presents a health risk in the event of internal contamination (intake by ingestion, inhalation or injection) or direct contact with the skin.

As polonium-210 is found everywhere in the environment, humans are constantly exposed to contamination by inhalation and ingestion. The effective dose due to 210Po in the adult is approximately 0.07 mSv per year. Polonium-210 intake in humans is naturally excreted in varying quantities in the urine and feces, with uranium miners and smokers eliminating greater quantities than nonsmokers. Considering the balance between intake and excretion, the total activity found continuously in the average adult is estimated at some 30 Bq (or 0.18 picograms).

Polonium-210 is closely related to sulfur and selenium and its biological behavior resembles that of the rare earths. Following bodily intake, polonium-210 is carried rapidly to the soft tissues via the blood stream. The quantity absorbed following ingestion varies between

It is clear, polonium inside the body migrates to the blood stream and all round the body, It doesn't stay all in the lungs or stomach. And the body is capable of getting rid of it.

Its action on red blood cells at high doses is what causes radiation sickness.

Lead however...

Chronic lead exposure commonly causes haematological effects, such as anaemia, or neurological disturbances, including headache, irritability, lethargy, convulsions, muscle weakness, ataxia, tremors and paralysis.

There is some evidence that long-term occupational exposure to lead may contribute to the development of cancer. The International Agency for Research on Cancer (IARC) has classified inorganic lead compounds as probably carcinogenic to humans (Group 2A), meaning that there is limited evidence for carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. According to IARC, organic lead compounds are not classifiable as to their carcinogenicity to humans (Group 3), meaning that there is inadequate evidence for their carcinogenicity to humans."

Now in the case of polonium decay, we are looking at inorganic lead.

Looking at radon, which is more likely?, polonium 210 with a half life of 138 days and which is likely to be all over the body anyway and in the blood stream, or its precursor lead 210 which hangs around for years, probably in the lungs and is known to cause cancers in mice.

Litvinenko didnt die from cancer, he died from acute radiation sickness, Its a total red herring

Actually you end up with lead 210 in the lungs, that slowly decays to polonium 210 which gets absorbed by the body and excreted.

and huge doses - enough to migrate throughout his body and cause radiation sickness

Nothing to do with staying in the lungs and causing lung cancer years later, because it doesn't stay in the lungs

Lead however, does.

Indeed, but it rapidly decays, so some lead 210 will be produced in every inhalation you make.

Eventually *that* turns into polonium 210, which is absorbed by the body and excreted, or turns into stable lead.

Fred.

There's no point discussing this with TNP because he has the mindset that *all* DNA damage from low dose radiation exposure is repaired. While there is good evidence that the LNT model is conservative, I think the jury is still out on whether or not there are detectable levels of cancer attributable to background radiation. It is very hard to do the sums, you need large amounts of data, and there are always many confounding factors.

But, we know that people do, randomly, get cancer as a result of mutations. So while the DNA repair mechanism is very good, it is evidently not perfect. In theory, a single radioactive decay could cause DNA damage, and alpha particles are especially bad because they dump a lot of energy locally. And that is why I think there is some risk from low levels of radiation, especially from radon.

The point about radon (very different from Argon 41) is that at 200 Bq/m^3 you will have one decay per second from a lung-full. That will leave behind a radioactive polonium (or bismuth, or lead) atom. And that will decay as well, very likely before it is ejected by biological processes. So you get a steady, cumulative dose on a relatively small mass of tissue when you are breathing radon. The only way that can have

The Pickrell article in the link below thinks there is an effect. Pritchard & Gessel are more skeptical. Thompson mentions toxicity. Scientists disagree (at least, they do when they are doing science properly).

Have any comparisons (in terms of cancer rates) been done between populations that live in low-background areas, and those in either high background areas such as Dartmoor or at high altitudes?

the two i fiund suggested higher incidences of lung cancer around Dartmoor, especially in smokers. The incidence of cancer in Ramsar, Iran which is ten times higher radon, and is full of smokers, is actually lower than Iran in general.

The same effect was noted in a block of flats where cobalt 60 was inadvertently incorporated

"The conventional approach for radiation protection is based on the ICRP's linear, no threshold (LNT) model of radiation carcinogenesis, which implies that ionizing radiation is always harmful, no matter how small the dose. But a different approach can be derived from the observed health effects of the serendipitous contamination of 1700 apartments in Taiwan with cobalt-60 (T1/2 = 5.3 y). This experience indicates that chronic exposure of the whole body to low-dose-rate radiation, even accumulated to a high annual dose, may be beneficial to human health. Approximately 10,000 people occupied these buildings and received an average radiation dose of 0.4 Sv, unknowingly, during a 9?20 year period. They did not suffer a higher incidence of cancer mortality, as the LNT theory would predict. On the contrary, the incidence of cancer deaths in this population was greatly reduced?to about 3 per cent of the incidence of spontaneous cancer death in the general Taiwan public. In addition, the incidence of congenital malformations was also reduced?to about 7 per cent of the incidence in the general public. "

So it is already clear that radiation and cancer is much more complex than te average guardian reader can grasp

Neither am I claiming in a simplistic way that radiation below a threshold has *no* effect.

What seems to be the case is that the graph of cancer versus long term level is S shaped. At very low levels the chance of two identical mutations mutating DNA in a viable way is vanishingly small, whereas if for example the same amount of radiation is banged in as a single large exposure, the chance is much higher.

We have evolved that way because we are bathed in constant low level radiation, and that mechanism is in DNA because it stops over mutation.

That is what modern research is suggesting - that nearly everything we thought we knew about chronic low level radiation is wrong, and the legislation that is based on refuted theories is unnecessarily conservative.

Unfortunately that cuts no ice with a generation brought up on anti-nuclear articles in the guardian, new scientist and the BBC.

As broadly soft Marxists, their instinct was always to support the Russian funded eco movements and the CND. And believe in nuclear winter, mega death and the evil spectre of nuclear power with 'poisons that last for a thousand years' and instead place their faith in solar panels whose heavy metal toxic waste will last forever.