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RE: AW: Denver, BEWARE!
Hello, Wes,
Thanks for the explanation.
What surprised me is that there was no correlation between the altitude and
the slope change.
Another interesting item is that the overall average slope is about half of
what Cohen claims when it's unbinned.
I think I'll just keep an eye on the radon and be done with it.
What would you tell someone who is just at the actionable EPA borderline in
his home? No one smokes. I told him, I'm not an expert in the area, but I
wouldn't go crazy--I'd just try and exchange some air.
Cheers,
Richard
At 07:59 PM 12/20/2004 -0500, Wesley wrote:
>Richard and All,
>
>Yes, it gets complicated. Let me try to explain.
>
>The slope "B" is the relationship between lung cancer and RADON, not
>altitude. When you stratify the slope "B" for radon in 10 bins, each with
>very similar altitude, the slope "B" becomes less negative, on average.
>
>What I found really amazing when I did the research was that the graph of
>lung cancer versus radon looked no more correlated than the graph of lung
>cancer and altitude. As a working hypothesis (not a final conclusion) I
>would say that both increased radon and reduced oxygen concentration (higher
>altitude) protect against lung cancer.
>
>Thanks for graphing the data!
>
>Best regards,
>Wes
>Wesley R. Van Pelt, PhD, CIH, CHP
>Wesley R. Van Pelt Associates, Inc.
>
>
>-----Original Message-----
>From: Richard L. Hess [mailto:lists@richardhess.com]
>Sent: Sunday, December 19, 2004 10:58 PM
>To: RuthWeiner@AOL.COM; WesVanPelt@att.net; radsafe@list.vanderbilt.edu
>Subject: Re: AW: Denver, BEWARE!
>
>At 05:54 PM 12/19/2004 -0500, RuthWeiner@AOL.COM wrote:
> >Richard et al:
> >
> >I think "correcting for oxygen" means correcting for the fact that the
> >atmospheric pressure is less at 5280 feet than at sa leve, so there is
> >less oxygen available. This is a well known phenomenon (we are a mile
> >high here in Albuq. also). I don't think the idea was that oxygen is a
> >carcinogen, but that metabolism, breathing rate, saturation of hemoglobin,
> >etc are affected
> >
> >Ruth
> >
>
>Thanks, Ruth and Franz,
>
>I'm still confused, because Franz reminded me of the graph I made on an
>airplane a few years ago--and at altitude (IIRC about 41,000 feet) we were
>up at about 250µR per hour (as measured on an Aware RM-70 pancake G-M
>tube)--and I understood from RADSAFE at the time, that the G-M tube
>under-reports the high-energy. For the graph, please see
>http://www.richardhess.com/rad/lax_chi.jpg
>
>When I'm a mile high, I breathe harder than at sea level, so I naturally
>thought that the body makes up for the thinner air by trying to inhale more
>of it.
>
>So we have Cohen's data for Radon, Wes's data for altitude, and then Franz
>throwing in the reduced shielding aspect. Even with Wes correcting for
>altitude I'm not sure I understand the effect that he's discussing. I took
>the data from Table 2 of Van Pelt's paper and did a simple graph in Excel.
>I even added a 2nd order polynomial trend line. See
>http://www.richardhess.com/rad/cohen_binned_by_van_pelt.jpg
>
>I still don't see a correlation between the slope "B" of the overall data
>and altitude. I see changes, I don't see a correlation--but I never was
>very good at statistics. Several years ago, I worked on a project with a
>Caltech statistician and he and I kept trying to get the other to explain,
>in simple terms, what was going on. I think we both saw the light that it
>was hard to reduce our own practice to simple terms the other could
>understand--but we got through it.
>
>Cheers,
>
>Richard
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