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RE: Radon and Never Smokers
Tom, Jim, Radsafers,
Why not have a critical look at the www.precura.de website; under
Publications you can download the Schneeberg study "High residential
radon health effects in Saxony". There are long-term exposure
categories from <50 to >1500 Bq/m^3. In Germany the medical records as
well as the occupational records are relatively reliable. This report
does not seem to indicate an increased lung cancer risk up to
residential radon levels of 1000 Bq/m^3, and suggests a reduced relative
risk between the lowest category and 1000 Bq/m^3. Any comment? I include
a summary:
""Analysis of the likelihood of female inhabitants of Schneeberg and
Schlema (Saxony) contracting lung cancer as a result of radon exposure
in dwellings arising from mining and geologically-induced factors, and
studies concerning the reconstruction of exposure".
J. Conrady, K. Martin, A. Poffijn, M. Tirmarche, J. Lembcke, D.M. Thai,
H. Martin
Executive Summary
The available data from indoor radon studies were considered by BEIR VI
to be not yet sufficient to develop a general risk-assessment model or
to estimate precisely the magnitude of risk posed by radon in houses. In
its conclusions, BEIR VI recommends that the power of an indoor radon
study to detect an excess risk could be enhanced by targeting special
populations, such a population with high exposures, a broad range of
exposures, and low residential mobility. The preferential use of
non-smokers was not recommended. Otherwise the Schneeberg study
completely complies with BEIR VI recommendations regarding its
conditions.
An increased and significant OR could be established with the Schneeberg
study by two forms of analysis in the higher exposure-categories only.
Below a radon-concentration of 48 * 106 (Bqh/m³) accordingly 1000 Bq/m³
and a residential duration of 20 years the OR is not elevated.
Significantly elevated OR after both forms of the analysis are
detectable at the exposition level of > 1500 Bq/m³ .
The risk estimation of the Schneeberg study for lung cancer from indoor
radon is not in accordance with the results from miners and population
studies, which state an excess risk for 10%/100 Bq/m³ radon exposure. If
such risk estimates are true, in the highly exposed population of
Schneeberg such lung cancer risks must have been easily established.
That is not the case. From the risk estimate of the Schneeberg study
even a safe threshold value was found and a significantly elevated risk
appeared at >1.500 Bq/m³ only. Great efforts were taken to explain such
discrepancies in comparison to the results from other studies. One
reason could be the favourable study conditions of the Schneeberg study
(highly exposed population, mainly non-smoking women, exposed fraction
very high and a relatively high power etc.). The other reasons are
related to characteristics of the other studies especially with the low
exposure to indoor radon and a high exposure to tobacco smoke and a low
power. The results from the Schneeberg study are on the other hand
enough founded to make further research in that key population a top
priority and hesitate to introduce prematurely legal limits for indoor
radon."
Chris Hofmeyr
chofmeyr@nnr.co.za
-----Original Message-----
From: Tom Mohaupt [mailto:tom.mohaupt@WRIGHT.EDU]
Sent: Tuesday, June 26, 2001 6:27 PM
To: Jim Nelson; RadSafe
Subject: Re: Radon and Never Smokers
Indeed an interesting study. Thanks Jim for bringing it to our
attention.
Some comments:
1) The relative risks presented in Table 5 adjusted with missing data
imputed. They state the relative risk as 1.55 for radon concentrations
greater than 140 Bq/m^3. From Table 4, concentrations greater than 200
Bq/m^3 (with imputed data) give a RR of 1.067 [Cases: 13/258; Controls:
23/487]. Big difference. New math?
2) Looking over Table 4, there really isn't a discernible difference
between the cases and controls. Any differences in percentages can
easily
be swayed by one or two cases (or controls) improperly grouped.
3) It doesn't look like Sweden has a genuine radon problem. The control
distribution of radon concentration should represent the country at
large.
In such case, less than 5% of the population is exposed to radon
concentration more than 200 Bq/m^3 (the European action level for new
construction) and 0.6% of the population is exposed to radon
concentrations
more than 400 Bq/m^3 ( the action level for existing structures).
4) I would have liked to see the authors include higher categories of
radon
concentrations, such as 800 and 1200 Bq/m^3, since these levels do exist
and are biologically more important. Using administrative values as data
cutoff point is OK as long as higher cutoff values are presented for
comparison (i.e., 400 Bq/m^3 to infinity represents an enormous spectrum
of
concentrations).
Tom
Jim Nelson wrote:
>
> Interesting article recently published.
> http://www.epidem.com/article.asp?ISSN=1044-3983&VOL=12&ISS=4&PAGE=396
>
> Residential Radon and Lung Cancer among Never-Smokers in Sweden
>
> Frédéric Lagarde1; Gösta Axelsson2; Lena Damber3; Hans Mellander4;
Fredrik
> Nyberg1; Göran Pershagen1,5
>
> >From the 1Institute of Environmental Medicine, Karolinska Institutet,
> Stockholm;
> 2Department of Environmental Medicine, Göteborg University,
Gothenburg;
> 3Department of Oncology, University Hospital, Ume;
> 4Swedish Radiation Protection Institute, Stockholm; and
> 5Department of Environmental Health, Stockholm County Council,
Stockholm,
> Sweden.
>
> EPIDEMIOLOGY 2001;12:396-404
>
>
------------------------------------------------------------------------
--------
>
> In this study, we attempted to reduce existing uncertainty about the
> relative risk of lung cancer from residential radon exposure among
> never-smokers. Comprehensive measurements of domestic radon were
performed
> for 258 never-smoking lung cancer cases and 487 never-smoking controls
from
> five Swedish case-control studies. With additional never-smokers from
a
> previous case-control study of lung cancer and residential radon
exposure in
> Sweden, a total of 436 never-smoking lung cancer cases diagnosed in
Sweden
> between 1980 and 1995 and 1,649 never-smoking controls were included.
The
> relative risks (with 95% confidence intervals in parentheses) of lung
cancer
> in relation to categories of time-weighted average domestic radon
> concentration during three decades, delimited by cutpoints at 50, 80,
and
> 140 Bq m-3, were 1.08 (0.8-1.5), 1.18 (0.9-1.6), and 1.44 (1.0-2.1),
> respectively, with average radon concentrations below 50 Bq m-3 used
as
> reference category and with adjustment for other risk factors. The
data
> suggested that among never-smokers residential radon exposure may be
more
> harmful for those exposed to environmental tobacco smoke. Overall, an
excess
> relative risk of 10% per 100 Bq m-3 average radon concentration was
> estimated, which is similar to the summary effect estimate for all
subjects
> in the main residential radon studies to date.
>
> Keywords: case-control study; lung neoplasms; risk assessment; radon;
> never-smokers; cocarcinogenesis; tobacco smoke pollution;
environmental
> exposures
>
> _________________________________________________________________
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>
>
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--
Thomas Mohaupt, M.S., CHP
University Radiation Safety Officer
104 Health Sciences Bldg
Wright State University
Dayton, Ohio 45435
tom.mohaupt@wright.edu
(937) 775-2169
(937) 775-3761 (fax)
"An investment in knowledge gains the best interest." Ben Franklin
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