Mrs Trellis
Well-known member
Does anyone have figures for the show caves - to see whether the extractor fans make a difference? Given the basalt above Peak-Speedwell one would imagine this area isn't great.
Radon in Giants
- Thread starter pwhole
- Start date
pwhole
Well-known member
I'm not sure if the lava itself would be a problem for the show cave - if you mean as an 'umbrella'? I've attached a crude overlay (the BGS maps are very crude!) of the Cavedale Lava (pink colouring) over the Peak-Speedwell system, and it only actually covers a small amount. I don't know how accurate the mapping of the outcrop actually is, but I doubt it's much more than this. The only place I've seen underground with actual physical evidence of the lava is at the top of Victoria Aven, either within the choke at the very top of Victoria Chamber, or at the base of George Cooper Aven. I also found a very large animal rib-bone in the Victoria Chamber choke a few years ago (not the one noted by JNC years before) which I gave to Andrew Chamberlain, so something must have been open to surface at one point, though it's just grass now. There is a large burial barrow adjacent, which is a Scheduled Monument, so maybe they dug a bit too deep into an existing swallow hole when they created it?
The Peak-Speedwell survey is relatively accurate, and Victoria Aven can be seen to be outside the outcrop. In which case the outcrop mapping is definitely inaccurate, although to be fair to the BGS they didn't have access to the top of Victoria Aven when they were doing the mapping. Though they know where to sink a borehole now
The blocks at the base of George Gooper Aven are very large, and are dark green and unmistakably basalt - I took a small lump out which is in the Chapel kitchen cabinet. Given the roof directly above this point is solid limestone, this means they must have fallen down the aven from above and bounced down the further pitches. There's probably more covered in mud lower down in Echo Chamber. The micro-guide for this area does say that a climb up is possible into lava blocks, so I suspect the lava literally caps the development around there.
The Peak-Speedwell survey is relatively accurate, and Victoria Aven can be seen to be outside the outcrop. In which case the outcrop mapping is definitely inaccurate, although to be fair to the BGS they didn't have access to the top of Victoria Aven when they were doing the mapping. Though they know where to sink a borehole now
The blocks at the base of George Gooper Aven are very large, and are dark green and unmistakably basalt - I took a small lump out which is in the Chapel kitchen cabinet. Given the roof directly above this point is solid limestone, this means they must have fallen down the aven from above and bounced down the further pitches. There's probably more covered in mud lower down in Echo Chamber. The micro-guide for this area does say that a climb up is possible into lava blocks, so I suspect the lava literally caps the development around there.
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tdobson
Member
So the main question I have about Radon (and I realise this is stirring up the can of worms), goes something like this:
"At what point does the risk of lung cancer from Radon exposure get similar to the risk from smoking?"
At a glance, it'd seem like one would know this, because there is data for people who smoke and don't smoke, who are living in relatively low-radony (by peak cave standards!) areas.
The issue I can see is that I'm choosing to expose myself (nonsmoker) to relatively high concentrations of Radon, albeit for smallish amounts of time - but no-one suggests if the risk from higher concentrations is linear or otherwise - as far as I can see.
Anyone want to present any "fag packet" workings or theories?
Pun intended ofc.
Whoops - Sorry Sam! Still getting my bearing on who can do what here!
"At what point does the risk of lung cancer from Radon exposure get similar to the risk from smoking?"
At a glance, it'd seem like one would know this, because there is data for people who smoke and don't smoke, who are living in relatively low-radony (by peak cave standards!) areas.
The issue I can see is that I'm choosing to expose myself (nonsmoker) to relatively high concentrations of Radon, albeit for smallish amounts of time - but no-one suggests if the risk from higher concentrations is linear or otherwise - as far as I can see.
Anyone want to present any "fag packet" workings or theories?
Pun intended ofc.
SamT said:
Whoops - Sorry Sam! Still getting my bearing on who can do what here!
Mark
Well-known member
tdobson said:
Doug Nash would have been the man to ask on this one, he smoked cigarettes from the age of 11, started smoking a pipe 18hrs a day in his 50s, because cigarettes were bad for him.
He spent most of his life in Radon riddled mines (work and play) and lived in a high radon area in Eyam
Lived to 95
Pete K
Well-known member
tdobson said:
Although I can't give you the answer you want, I can point you at the section of the BCA's new Radon Underground document that refers to health risk.
https://british-caving.org.uk/wiki3/lib/exe/fetch.php?media=publications_information:bca_radon_underground_2nd_ed.pdf
Section 1.3 & 1.4 page 8.
Mark is right to highlight that exposure to radon does not necessarily increase the risk to the individual, as in Doug's case perhaps, although anecdotally, there is seemingly a high correlation between lung cancer and cavers. I just hope I fall on the Doug side of the genetic spectrum on this.
andrewmcleod
Well-known member
I believe the most common assumption with hazard due to low levels of radiation exposure is the linear no-threshold model, which basically says the risk is directly proportional to the exposure all the way down to zero dose, zero risk. Obviously the smaller the dose, the harder it is to demonstrate outcomes, so it's an assumption that the behaviour observed at higher doses continues at lower doses. Various people have proposed that at some arbitrary low dose the hazard suddenly disappears, or radiation even becomes helpful, but there's not really good evidence for that.
At higher doses, things are a bit different (e.g. the same dose in a shorter time is more dangerous than spread out over time) but I suspect that isn't relevant? Someone with radiological experience would probably know.
So the mainstream assumption is that there is no 'safe' dose of ionising radiation: you could go in Giant's once, be very unlucky and get lung cancer. Although equally there is background radiation everywhere, so you could just get lung cancer outside the cave if you were unlucky.
The dose limits are just to keep individual risks extremely low, I think, not because there is a 'safe' dose.
At higher doses, things are a bit different (e.g. the same dose in a shorter time is more dangerous than spread out over time) but I suspect that isn't relevant? Someone with radiological experience would probably know.
So the mainstream assumption is that there is no 'safe' dose of ionising radiation: you could go in Giant's once, be very unlucky and get lung cancer. Although equally there is background radiation everywhere, so you could just get lung cancer outside the cave if you were unlucky.
The dose limits are just to keep individual risks extremely low, I think, not because there is a 'safe' dose.
The correlation of lung cancer to cavers may also be due to dust inhalation, rather than radon, or it may just be because the majority of those now over 60 smoked when they were younger (or were subjected to it passively in huts, pubs & underground).
Genetics are also more important than (reasonable) dose levels, as some people are much more susceptible than others, but government can't legislate on that.
Genetics are also more important than (reasonable) dose levels, as some people are much more susceptible than others, but government can't legislate on that.
mrodoc
Well-known member
The effect of radon on smokers is synergistic ie smoking amplifies the risk of lung cancer with co exposure many fold (cannot recall how many). I have always maintained that with the number of active cavers in the UK it would be very difficult to establish a link once you have removed all the cavers who smoke. Nowadays the numbers of cavers who smoke has dropped (if they behave like the general population) so perhaps a caving epidemiologist could look at this again.
Speleotron
Member
Mark said:
You do get survivorship bias with this kind of story though!
Brains
Well-known member
Back in the days of carbide and ladders, smoking underground was a common thing. Sparking up from a stinky was almost a pleasure in itself. In these enlightened times electrons, stinkies and smokes are generally frowned upon everywhere. In some backwards places fireworks etc. are still seen as acceptable to a minority...mrodoc said:
The image a beardy caver in grots on a ladder, hiding under a texolex and stinky with a dog end glued to a lip is not that out of date in some respects
pwhole
Well-known member
Lurking on someone's phone is a photo of me at the top of Rowter Hole shaft waiting to go down, with a rather large cone in my mouth. And I'd shaved only that morning. I honestly don't know what to think about it - I smoke, and I cave primarily in Castleton, though I try to avoid 'pointless' trips generally. I guess I too have to hope for genetic benefits, as it's probably too late to make that much difference now. I smoke less than I used to, and I've certainly caved less since lockdown, but I suspect one or two trips a week for a lot of years is hard to wipe out.
adep
Member
I did some Radon measurements for Manchester university about 12 years ago, we didn?t find Giants that bad at the time, although as stated it can vary a lot, knowing what I know I would be far more wary of Oxlow, especially in the large chambers at the bottom, we found very high readings there, to the point where I won?t go into Oxlow/ Maskill more than a couple of times a year
Pitlamp
Well-known member
What time of year was that Giants study done Adep, out of interest?
I try not to think what sort of dose we must have got on all the round the clock trips in Peak Cavern's Far Sump Extension before the JH and Titan surface connections were made, allowing draughts to begin. Thank goodness I don't smoke.
I try not to think what sort of dose we must have got on all the round the clock trips in Peak Cavern's Far Sump Extension before the JH and Titan surface connections were made, allowing draughts to begin. Thank goodness I don't smoke.
Groundhog
Member
