[ RadSafe ] Hormesis effect in a case-controlled indoor radon study
jkotton at usgs.gov
Fri Feb 15 09:40:57 CST 2008
This is a forward of a study posted by Bill Field to the RADONPROFESSIONALS
The results suggest a hormetic effect to exposures up to about 4 pCi/L (150
Bq/m3), then an enhanced effect at about 7 pCi/L (250 Bq/m3).
U.S. Geological Survey
Uranium, radium, radon specialist
From: International Web Resource for Radon Professionals
[mailto:RADONPROFESSIONALS at LIST.UIOWA.EDU] On Behalf Of Field, R W
Sent: Friday, February 15, 2008 1:12 AM
To: RADONPROFESSIONALS at LIST.UIOWA.EDU
Subject: [RADONPROFESSIONALS] Thompson et al .Radon Study
My guess is that there will likely be quite a few letters-to-the-editor
commenting on this recently published study (attached).
Thompson et al.
Abstract-A study of lung cancer risk from residential radon
exposure and its radioactive progeny was performed with 200
cases (58% male, 42% female) and 397 controls matched on
age and sex, all from the same health maintenance organization.
Emphasis was placed on accurate and extensive year-long
dosimetry with etch-track detectors in conjunction with careful
questioning about historic patterns of in-home mobility.
Conditional logistic regression was used to model the outcome
of cancer on radon exposure, while controlling for years of
residency, smoking, education, income, and years of job exposure
to known or potential carcinogens. Smoking was accounted
for by nine categories: never smokers, four categories
of current smokers, and four categories of former smokers.
Radon exposure was divided into six categories (model 1) with
break points at 25, 50, 75, 150, and 250 Bq m_3, the lowest
being the reference. Surprisingly, the adjusted odds ratios
(AORs) were, in order, 1.00, 0.53, 0.31, 0.47, 0.22, and 2.50
with the third category significantly below 1.0 (p < 0.05), and
the second, fourth, and fifth categories approaching statistical
significance (p < 0.1). An alternate analysis (model 2) using
natural cubic splines allowed calculating AORs as a continuous
function of radon exposure. That analysis produces AORs
that are substantially less than 1.0 with borderline statistical
significance (0.048 < p < 0.05) between approximately 85 and
123 Bq m_3. College-educated subjects in comparison to highschool
dropouts have a significant reduction in cancer risk after
controlling for smoking, years of residency, and job exposures
with AOR _ 0.30 (95% CI: 0.13, 0.69),
RADONPROFESSIONALS - http://list.uiowa.edu/archives/radonprofessionals.html
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Thompson et al. 2008.pdf
Size: 307023 bytes
Desc: not available
More information about the RadSafe