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radon - documentation of exposure histories for Iowa study
Jim Muckerheide,
Ray Johnson may not be an epidemiologist, but the point was that Ray knows a
few things about radon exposure assessment. As far as Phillipe Dupont, he
is a frequent poster of emails on your Radiation and Science listserv and an
known anti LNT proponent.
If the Iowa study did not find an association, then they may have said the
power was insufficient to detect an association as is likely the case in
many studies with poor exposure ascertainment. But, the Iowa study did find
an association so therefore the sample size was of sufficient power to
detect an association.
I saw your "explanation" given to Les. It was nonsensical to me as it
apparently was to Les. As far as your misrepresentations, I am not sure
where to start. The latest item you have tried to mislead people with is
that the Iowa Study did not obtain individual exposure histories for each
subject. Your insistence is that because someone lives in Iowa, that have to
be exposed to high radon levels. As Les, pointed out. In the Iowa study
half, the people in the study were exposed to less than 4 pCi/L (average
15--year exposure). Their exposure data was log normally distributed (that
means they had a lot of data for lower exposed individuals).
The Iowa study did an incredible job documenting individual exposure
including many supporting papers as Les has pointed out to me. On one hand
we have your misrepresentation and on the other hand we have these detailed
papers below laying out how they accounted for radon exposure.
------------------------------------------
Citation: Field RW, Smith BJ, Brus CP, Lynch CF, Neuberger JS, Steck DJ,
Retrospective temporal and spatial mobility of adult Iowa women., Risk Anal
18: 5, 575-84, Oct, 1998.
Abstract
Human exposure assessments require a linkage between toxicant concentrations
in occupied spaces and the receptor's mobility pattern. Databases reporting
distinct populations' mobility in various parts of the home, time outside
the home, and time in another building are scarce. Temporal longitudinal
trends in these mobility patterns for specific age and gender groups are
nonexistent. This paper describes subgroup trends in the spatial and
temporal mobility patterns within the home, outside the home, and in another
building for 619 Iowa females that occupied the same home for at least 20
years. The study found that the mean time spent at home for the participants
ranged from a low of 69.4% for the 50-59 year age group to a high of 81.6%
for the over 80-year-old age group. Participants who lived in either one- or
two- story homes with basements spent the majority of their residential
occupancy on the first story. Trends across age varied for other subgroups
by number of children, education, and urban/rural status. Since all of these
trends were nonlinear, they indicate that error exists when assuming a
constant, such as a 75% home occupancy factor, which has been advocated by
some researchers and agencies. In addition, while aggregate data, such as
presented in this report, are more helpful in deriving risk estimates for
population subgroups, they cannot supplant good individual-level data for
determining risks.
------------------------------------------------------------
Medline ID: 21270976
Citation: Field RW, Steck DJ, Smith BJ, Brus CP, Fisher EF, Neuberger JS,
Lynch CF, The Iowa radon lung cancer study--phase I: Residential radon gas
exposure and lung cancer., Sci Total Environ 272: 1-3, 67-72, May14, 2001.
Abstract
Exposure to high concentrations of radon (222Rn) progeny produces lung
cancer in both underground miners and experimentally-exposed laboratory
animals. The goal of the study was to determine whether or not residential
radon exposure exhibits a statistically significant association with lung
cancer in a state with high residential radon concentrations. A
population-based, case-control epidemiologic study was conducted examining
the relationship between residential radon gas exposure and lung cancer in
Iowa females who occupied their current home for at least 20 years. The
study included 413 incident lung cancer cases and 614 age-frequency-matched
controls. Participant information was obtained by a mailed-out questionnaire
with face-to-face follow-up. Radon dosimetry assessment consisted of five
components: (1) on-site residential assessment survey; (2) on-site radon
measurements; (3) regional outdoor radon measurements; (4) assessment of
subjects' exposure when in another building; and (5) linkage of historic
subject mobility with residential, outdoor, and other building radon
concentrations. Histologic review was performed for 96% of the cases.
Approximately 60% of the basement radon concentrations and 30% of the first
floor radon concentrations of study participants' homes exceeded the US
Environmental Protection Agency action level of 150 Bq m(-3) (4 pCi l(-1)).
Large areas of western Iowa had outdoor radon concentrations comparable to
the national average indoor value of 55 Bq m(-3) (1.5 pCi l(-1)). Excess
odds of 0.24 (95% CI = -0.05-0.92) and 0.49 (95% CI = 0.03-1.84) per 11
WLM(5-19) were calculated using the continuous radon exposure estimates for
all cases and live cases, respectively. Slightly higher excess odds of 0.50
(95% CI = 0.004-1.80) and 0.83 (CI = 0.11-3.34) per 11 WLM(5-19) were noted
for the categorical radon exposure estimates for all cases and the live
cases. A positive association between cumulative radon gas exposure and lung
cancer was demonstrated using both categorical and continuous analyses. The
risk estimates obtained in this study indicate that cumulative radon
exposure presents an important environmental health hazard.
----------------------------------------------------------------
Environmental Health Perspectives Volume 107, Number 11, November 1999
Intercomparison of Retrospective Radon Detectors
R. William Field,1 Daniel J. Steck,2 Mary Ann Parkhurst,3 Judy A. Mahaffey,3
and Michael C.R. Alavanja4
1Department of Epidemiology, College of Public Health, University of Iowa,
Iowa City, Iowa, USA
2Physics Department, St. John's University, Collegeville, Minnesota, USA
3Pacific Northwest National Laboratory, Richland, Washington, USA
4National Cancer Institute, Bethesda, Maryland, USA
Abstract
We performed both a laboratory and a field intercomparison of two novel
glass-based retrospective radon detectors previously used in major radon
case-control studies performed in Missouri and Iowa. The new detectors
estimate retrospective residential radon exposure from the accumulation of a
long-lived radon decay product, 210Pb, in glass. The detectors use track
registration material in direct contact with glass surfaces to measure the
-emission of a 210Pb-decay product, 210Po. The detector's track density
generation rate (tracks per square centimeter per hour) is proportional to
the surface -activity. In the absence of other strong sources of -emission
in the glass, the implanted surface -activity should be proportional to the
accumulated 210Po, and hence to the cumulative radon gas exposure. The goals
of the intercomparison were to a) perform collocated measurements using two
different glass-based retrospective radon detectors in a controlled
laboratory environment to compare their relative response to implanted
polonium in the absence of environmental variation, b) perform collocated
measurements using two different retrospective radon progeny detectors in a
variety of residential settings to compare their detection of
glass-implanted polonium activities, and c) examine the correlation between
track density rates and contemporary radon gas concentrations. The
laboratory results suggested that the materials and methods used by the
studies produced similar track densities in detectors exposed to the same
implanted 210Po activity. The field phase of the intercomparison found
excellent agreement between the track density rates for the two types of
retrospective detectors. The correlation between the track density rates and
direct contemporary radon concentration measurements was relatively high,
considering that no adjustments were performed to account for either the
residential depositional environment or glass surface type. Preliminary
comparisons of the models used to translate track rate densities to average
long-term radon concentrations differ between the two studies. Further
calibration of the retrospective detectors' models for interpretation of
track rate density may allow the pooling of studies that use glass-based
retrospective radon detectors to determine historic residential radon
exposures. Key words: case-control studies, dose-response relationship
(radiation), epidemiologic methods, epidemiologic studies, lung neoplasms,
radon, radon progeny, smoking. Environ Health Perspect 107:905-910 (1999).
[Online 15 October 1999]
http://ehpnet1.niehs.nih.gov/docs/1999/107p905-910field/abstract.html
Address correspondence to R.W. Field, College of Public Health, Department
of Epidemiology, N222 Oakdale Hall, University of Iowa, Iowa City, IA 52242
USA. Telephone: (319) 335-4413. Fax: (319) 335-4747. E-mail:
bill-field@uiowa.edu
We thank J. Huber, C. Greaves, G. Buckner, J. Jesse, and E. Berger for their
assistance with data collection. We also thank C. Lynch and J. Lubin for
their reviews of previous versions of this manuscript.
NCI contract 263-MQ-820009 and NIEHS grant P30 ESO5605 supported this
research. This report is solely the responsibility of the authors and does
not necessarily reflect the official views of the NCI, NIEHS, or NIH.
----------------------------------------------------------------
Medline ID: 99122934
Citation: Steck DJ, Field RW, Lynch CF, Exposure to atmospheric radon.,
Environ Health Perspect 107: 2, 123-7, Feb, 1999.
Address: Department of Physics
Abstract
We measured radon (222Rn) concentrations in Iowa and Minnesota and found
that unusually high annual average radon concentrations occur outdoors in
portions of central North America. In some areas, outdoor concentrations
exceed the national average indoor radon concentration. The general spatial
patterns of outdoor radon and indoor radon are similar to the spatial
distribution of radon progeny in the soil. Outdoor radon exposure in this
region can be a substantial fraction of an individual's total radon exposure
and is highly variable across the population. Estimated lifetime effective
dose equivalents for the women participants in a radon-related lung cancer
study varied by a factor of two at the median dose, 8 mSv, and ranged up to
60 mSv (6 rem). Failure to include these doses can reduce the statistical
power of epidemiologic studies that examine the lung cancer risk associated
with residential radon exposure.
-----------------------------------
Medline ID: 99005221
Citation: Fisher EL, Field RW, Smith BJ, Lynch CF, Steck DJ, Neuberger JS,
Spatial variation of residential radon concentrations: the Iowa Radon Lung
Cancer Study., Health Phys 75: 5, 506-13, Nov, 1998.
Abstract
Homeowners and researchers frequently estimate the radon concentrations in
various areas of the home from a single radon measurement often performed in
the home's basement. This study describes the spatial variation of radon
concentrations both between floors and between rooms on the same floor. The
geometric mean basement and first floor radon concentrations for one-story
homes were 13.8% and 9.0% higher, respectively, as compared to their
counterparts in two-story homes. The median first floor/basement ratio of
radon concentrations for one-story homes was 0.60. The median ratios between
first floor/basement and second floor/basement for two-story homes were 0.51
and 0.62, respectively. The mean coefficient of variation for detectors
placed on the same floor was 9.5%, which was only 2.6% higher than the mean
coefficient of variation found for collocated (duplicate) quality control
detectors. The wide individual variations noted in radon concentrations
serve as a reminder of the importance of performing multiple radon
measurements in various parts of the home when estimating home radon
concentrations.
-------------------------------------------------------
Field, R.W., Lynch, C.F., Steck, D.J. and Fisher, E.F.. Dosimetry Quality
assurance: the Iowa residential radon lung cancer study. Radiation
Protection Dosimetry. 78(4): 295-303, 1998
-----------------------------------------------
Medline ID: 96384408
Citation: Field RW, Steck DJ, Lynch CF, Brus CP, Neuberger JS, Kross BC,
Residential radon-222 exposure and lung cancer: exposure assessment
methodology., J Expo Anal Environ Epidemiol 6: 2, 181-95, Apr-Jun, 1996.
Abstract
Although occupational epidemiological studies and animal experimentation
provide strong evidence that radon-222 (222Rn) progeny exposure causes lung
cancer, residential epidemiological studies have not confirmed this
association. Past residential epidemiological studies have yielded
contradictory findings. Exposure misclassification has seriously compromised
the ability of these studies to detect whether an association exists between
222Rn exposure and lung cancer. Misclassification of 222Rn exposure has
arisen primarily from: 1) detector measurement error; 2) failure to consider
temporal and spatial 222Rn variations within a home; 3) missing data from
previously occupied homes that currently are inaccessible; 4) failure to
link 222Rn concentrations with subject mobility; and 5) measuring 222Rn gas
concentration as a surrogate for 222Rn progeny exposure. This paper examines
these methodological dosimetry problems and addresses how we are accounting
for them in an ongoing, population-based, case-control study of 222Rn and
lung cancer in Iowa.
--------------------------------------------
Medline ID: 20329535
Citation: Field RW, Steck DJ, Smith BJ, Brus CP, Fisher EL, Neuberger JS,
Platz CE, Robinson RA, Woolson RF, Lynch CF, Residential radon gas exposure
and lung cancer: the Iowa Radon Lung Cancer Study., Am J Epidemiol 151: 11,
1091-102, Jun1, 2000.
Abstract
Exposure to high concentrations of radon progeny (radon) produces lung
cancer in both underground miners and experimentally exposed laboratory
animals. To determine the risk posed by residential radon exposure, the
authors performed a population-based, case-control epidemiologic study in
Iowa from 1993 to 1997. Subjects were female Iowa residents who had occupied
their current home for at least 20 years. A total of 413 lung cancer cases
and 614 age-frequency-matched controls were included in the final analysis.
Excess odds were calculated per 11 working-level months for exposures that
occurred 5-19 years (WLM(5-19)) prior to diagnosis for cases or prior to
time of interview for controls. Eleven WLM(5-19) is approximately equal to
an average residential radon exposure of 4 pCl/liter (148 Bq/m3) during this
period. After adjustment for age, smoking, and education, the authors found
excess odds of 0.50 (95% confidence interval: 0.004, 1.81) and 0.83 (95%
percent confidence interval: 0.11, 3.34) using categorical radon exposure
estimates for all cases and for live cases, respectively. Slightly lower
excess odds of 0.24 (95 percent confidence interval: -0.05, 0.92) and 0.49
(95 percent confidence interval: 0.03, 1.84) per 11 WLM(5-19) were noted for
continuous radon exposure estimates for all subjects and live subjects only.
The observed risk estimates suggest that cumulative ambient radon exposure
presents an important environmental health hazard.
Don Smith
----------------------------------------------
>From: "Jim Muckerheide" <jmuckerheide@cnts.wpi.edu>
>To: "Rad health" <healthrad@hotmail.com>, <lescrable@hotmail.com>,
><jkotton@usgs.gov>
>CC: <radsafe@list.vanderbilt.edu>
>Subject: RE: radon - and tackling the issues
>Date: Tue, 15 Jan 2002 04:11:47 -0500
>
You haven't read, or perhaps understood, the problem. See the
explanation provided to Les. If you think something is "misleading," let me
know. It's just my take on the failure of radon case-control studies.
And why Iowa is the worst place, despite Field's efforts to relate a
lifetime of radon exposure to house measurements. It just can't work,
and the study is too small to produce a credible, replicable result.
Ray's a great guy, but his forte is HP training, and communication. If
you want an expert on radon health effects try Philippe Duport at U
Ottawa, with 40 years originally focused on the French miners and the
industry, then to Canada, as a regulator, and nor at the university. No
adverse radon effects at low-dose, low dose-rate, at much higher than
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