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Re: Lung cancer mortality from radon versus mortality from other cancers
Mark, Mike Ford and Radsafe friends
(I tested sending this message to myself, with the table. It came out OK.
I hope it does to everyone. If not, please e-mail me directly, I will send
things by fax)
For those interested, here is a summary of stats on the 11 cohorts subject
to Jay Lubin's et al. joint analysis (NIH publ. No. 94-3644, 1994)
One can note the wide disparity in number of Rn or Rn progeny measurements
between cohorts. Also worth noting is the wide range of duration of
employment at the facility in which the exposure used to calculate the risk
was acquired. Miners are a highly mobile bunch, particularly in North
America. It is no mystery that, at Beaverlodge for example, the company
(Eldorado) hired preferentially local miners (there were several other U and
Rn mines in the region), who therefore left a Rn mine to join Eldorado and
went to other local mines when they left Beaverlodge. Exposures accumulated
in other mines are not taken into account in risk calculations, hence a
systematic overestimation of Rn risk (how big is it ?). Perhaps the
question of '' other mine doses '' is worth looking at in the cohorts who
have a mean duration of employment of less than 10 years. In some mines
considered in the 11 cohorts, no measurements at all. exposures were
''reconstructed'', extrapolated, assigned from values obtained in nearby
mines, ....
Furthermore, the excess lung cancer incidence is attributed to radiation,
then the excess of lung cancers is due to the sum of all lung doses, from
all radiation sources, not that from Rn progeny alone. For the curious
mind, calculating non-radon doses and comparing them to Rn doses is quite
interesting ! Another source of systematic overestimation. NOTE: In all the
cohorts, there is no excess of cancer for organs other than lung, except
liver in Czech miners (alcohol consumption) and buccal cavity in French
miners (alcohol + cigarette) - see BEIR VI, table 4.3, p. 123).
To Mark, re iron Swedish miners: hematite (iron ore) is a known lung
carcinogen. Silica is another one listed as such by IARC. The incidence of
lung cancer in French iron miners is 3 to 5 (Anthoine, D., Lamy, P., De Ren
G., Braun, P., Cervoni, P., Petiet, G., Schwartz, P., Zuck, P. and Lamaze,
R. Le cancer bronchique des mineurs de fer de Lorraine, Arch. Mal. Prof.,
40, no. 2, 48-51, (1979). It is up to 15 in Czech iron miners (Isco , J and
Szollosova, M. Incidence of Lung cancer in Iron ore miners, Proceedings of
the International Conference on Low Dose Irradiation and Biological Defense
Mechanisms, Kyoto, Japan, 103-106, (1992). What are the respective
contributions of radon, silica, hematite in the excess lung cancer in
Swedish iron miners ?
(to reassure some of you, I spent ten years in radiation studies among
miners in French underground and open pit U mines, worked a few more years
in Elliot Lake in U mine dosimetry and did rad prot studies in high grade
mines in Saskatchewan)
Cohort
Number of measurements (Rn or Rn decay products)
Number of workers in the cohort
Number of measurements
per worker
Number of person.y
Average number of years of exposure
Number of lung cancer cases
ERR/WLM
Chinese tin miners
26500
13649
1.94
17607
1.3
936
0.16
(0.1-0.2)
Colorado uranium miners
43000
3347
12.85
16735
5.0
327
0.42
(0.3-0.7)
Czech uranium miners
120000
4284
28.01
31273
7.3
656
0.34
(0.2-0.6)
French uranium miners
1200000
1769
678.35
25882
14.6
45
0.36
(0.0-1.3)
New Mexico uranium miners
92000
3457
26.61
25581
7.4
68
1.72
(0.6-6.7)
Newfounland fluorspar miners
80
1751
0.05
8405
4.8
112
0.76
(0.4-1.3)
Ontario uranium miners
131000
21346
6.14
64048
3
282
0.89
(0.5-1.5)
Port Radium uranium miners
261
1420
0.18
4544
3.2
39
0.19
(0.1-0.6)
Radium Hill uranium miners
721
1457
0.49
1602
1.1
32
5.06
(1.0-12.2)
Swedish iron miners
80
1294
0.06
23033
17.8
79
0.95
(0.1-4.1)
Beaverlodge uranium miners
6900
6895
1.00
13101
1.9
58
2.21
(0.9-5.6)
Summary data for the eleven cohorts of underground miners exposed to
radon progeny
Philippe Duport
International Centre for Low Dose Radiation Research
University of Ottawa
555 King Edward Ave.
Ottawa, ON, Canada, K1N 6N5
Tel: (613) 562 5800, ext. 1270
pduport@uottawa.ca
----- Original Message -----
From: "Sonter Mark" <sonterm@EPA.NSW.GOV.AU>
To: "'Rad health'" <healthrad@HOTMAIL.COM>; <radsafe@list.vanderbilt.edu>
Sent: Thursday, January 17, 2002 10:13 PM
Subject: RE: Lung cancer mortality from radon versus mortality from other
cancers
> Dear various unidentified 'Dons',
>
> Well, I've been an RSO in uranium mines, and have followed the epi studies
> over a couple of decades; I don't doubt that radon daughters cause lung
> cancers, but I have to tell you that the risk estimates produced by the
> various miner epi studies and meta-studies are deficient because they
almost
> always fail, mostly don't even try, to take into account other in-mine
> airborne contaminants, such as the already-mentioned silica, nickel dust,
> arsenic dust, diesel soot, NOx, etc. etc. Now, all of these will be in
> general terms correlated negatively with mine ventilation effectiveness,
as
> will radon daughter concentration.....So, across the population of all
> mines, radon daughters and other nasties will tend to go up and down
> together.... Question is, how much of the risk of lung cancer arises from
> RnD, and how much from from other nasties??
>
> Those of us that have been around for some time (like Phil Duport) will
> remember the larger-than-life Al Dory excoriating Ed Radford for not
facing
> this issue in his study of the Swedish iron ore miners.
>
> Mark Sonter
>
> -----Original Message-----
> From: Rad health [SMTP:healthrad@HOTMAIL.COM]
> Sent: Friday, 18 January 2002 12:10
> To: radsafe@list.vanderbilt.edu
> Subject: RE: Lung cancer mortality from radon versus
> mortality from other cancers
>
> Michael Ford,
>
> Regarding your email below. From your tone, you really sound a bit
> agitated
> about this issue. But, our guess is what really bothers you is not
> the
> quality of the miner studies, but that the LNT is used to
> extrapolate risks
> down from them - are we right? But, really haven't we known for a
> very long
> time that something in the mines was killing people. No
> epidemiologic study
> could ever perfectly record all the exposures, but the researchers
> from
> various parts of the world likely strive to do the best science they
> can in
> the time periods the various studies were performed. What you can
> not help
> but notice is a pattern among all these studies (performed by
> different
> researchers in various parts of the world) that show an increasing
> positive
> trend with radon exposure that was estimated in various ways. If it
> was
> merely some other factor like silica, then it would also have to be
> in all
> the mines and co-correlate with radon.
>
>
>
>
> This e-mail is intended for the addressee(s) named and may contain
> confidential and/or privileged information. If you are not the intended
> recipient, please delete it immediately and notify the sender. Views
> expressed in this message are those of the individual sender, and are not
> necessarily the views of the Environment Protection Authority.
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