Radon myths and units

Originally Posted By: Caoimh?n P. Connell
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Hello Mr. Sutrina ?


I am new to this site. I am not an home inspector, rather I am a Forensic Industrial Hygienist. Some of the response you received are correct, some are quite entirely incorrect.

To answer your question ? the ?scale? of which you speak and run into the hundreds, thousands or even millions. The upper limit would practically (but not physically) be where an atmosphere contains 100% radon that is in ?dynamic equilibrium? (wherein the amount of radon being decayed is instantly being replaced with ?fresh radon.?) Concentrations of tens of thousands of pCi/l is not uncommon in ground water.

Regarding some of the response regarding risk and radon the comment that ALL exposure is unacceptable is simply untrue, and believe it or not, the risk is U-shaped with regard to exposure, and there is what is known as an ?hormetic? effect (some apparent benefit from exposure). In fact most of the popular information I have seen coming from Home Inspectors on radon is very sparse on science and very big on myth. In truth, ALL humans are daily exposed to radon ? it is not only inevitable but, according to the current school of thought, it may be vital to proper cell mutation (yes, some mutations are ?good.?).

Most of the EPA stuff on radon was geared toward about a 6th grade education, and lacks precision. If you would like to know the truth about radon, you may find my page interesting:

http://members.aol.com/piobin/radon.html

Regarding the pronounciation- ?PEEK-o? ore ?PIKE-o? are equally correct, and amongst science types, the prefix ?PIKE-o? will be heard more often. But it depends on where in the world one was raised.

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG


Originally Posted By: rmyers1
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WOW…your comments are very authoritative. Took the time to view your web site. Very informative. Thank you for the input.


Originally Posted By: jbushart
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What are your thoughts on this study, linking radon to Alzheimer’s and Parkinson’s diseases?



Alzheimer?s & Parkinson?s ? Could the Cause be Radon?



In a study conducted at the University of North Dakota, researchers discovered that the presence of radioactive radon daughters in the brains of non-smoking persons with Alzheimer?s and Parkinson?s disease was 10 times greater than it was in the brains of persons with no previous evidence of neurological disorders. Professor Glenn Lykken and Dr. Berislav Momcilovic assert their study demonstrates that indoor radon gas has the capacity to irreversibly infest the brain with the poisonous progeny of radioactive heavy metals.



Recently revised EPA risks assessments estimate 21,000 Americans die annually from radon induced lung cancer, 150% higher than their 1994 estimate. However, scientists are increasingly suspicious that radon may be linked to disease in other parts of the body as well.



When inhaled, radon gas accumulates in lipid tissue throughout the body with the highest concentration in the brain, bone marrow, and nervous system. Additionally, one-third of the inhaled radon decay products (radioactive particles produced when the gas decays) pass from the lungs into the blood stream indicating that the gas does not flow quickly in and out of the lungs, but lingers in the body.



Previous study at UND determined that once radon is rapidly absorbed into the body from the lung, it accumulates in the cranium resulting in increased gamma ray emissions from bismuth-214 (one of the radioactive radon decay products) and altered EEG signals.



While radon is a lipid-soluble gas that can move freely in and out of the brain despite the blood-brain barrier, none of the transmuted heavy metal radon daughters are soluble in the lipids, meaning they remain trapped in the brain where they emit gamma radiation and alpha particles resulting in both radiation and chemical injury to the brain cells.



Of keen interest was the unexpected discovery that the radioactivity selectively accrues to the brain proteins in the Alzheimer?s victims and to the brain lipids in the Parkinson?s victims. This pathognomonic distribution was inferred to reflect the increase of local chlorine availability to which to which the radon daughters bound selectively.



Once present, the most likely candidate for radiation injury appears to be the highly radiosensitive astrocytes rather than the more radioresistant neurons, which do not divide. Other studies have indicated the astrocytes may be involved in Alzheimer disease and the amyloid deposits and neurofibrillatory tangling observed with Alzheimer's may well reflect the response to radiation injury of the astrocytes.



Interestingly enough, the geographic distribution of Parkinson?s disease mortality is considerably higher in states with a greater radon potential, according to research by D.J. Lansak of the University of Kentucky and published in the Journal of Neurological Sciences.



University of North Dakota researchers are looking for more funding to continue their research. To access the study in its entirety, please go to www.radonnews.org or the Alzheimer Disease and Associated Disorders Magazine. Contact: Professor G.I. Lykken at UND at (701) 777 ? 3519.


--
Home Inspection Services of Missouri
www.missourihomeinspection.com

"We're NACHI. Get over it."

www.monachi.org

Originally Posted By: jhagarty
This post was automatically imported from our archived forum.



Caoimh?n P. Connell wrote:

?PIKE-o? ... amongst science types, the prefix ?PIKE-o? will be heard more often.

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG


Correct Pronunciation.


--
Joseph Hagarty

HouseMaster / Main Line, PA
joseph.hagarty@housemaster.com
www.householdinspector.com

Phone: 610-399-9864
Fax : 610-399-9865

HouseMaster. Home inspections. Done right.

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Hello Mr. Bushart:


The information, as reported, appears to be an entertainer?s (journalist) distillation of a scientific report. To a scientist, it rather reads like a six year old?s explanation of why a jet can fly. As a result, not much information can be gleaned from the report of the report of the study. One would have to return to the study and view the original document.

Also, the popular media constantly confuses association, correlation and causation. So the study may well demonstrate an association between radon and the diseases; indeed, it may even demonstrate correlation ? however, neither association nor correlation demonstrate causation. Once, during a lecture on toxicology and risk I was giving at Denver University, I underscored this problem by proving (using actual data) that storks cause babies in eastern Europe using the same logic employed by journalists.

The conspiracy of confusion, ignorance and media sensationalism can create some remarkable stirs- for example the flap over EMFs (electromagnetic fields) from high-tension power lines and leukemia demonstrated junk science at its best. The original report (Wertheimer and Leeper) discussed a "study" that was so badly designed, so poorly executed and poorly founded on actual science that it was immediately (immediately) discounted as bunk by real scientists who bothered to actually read the original paper.

The paper purported to demonstrate that EMFs caused cancer. In fact, as designed, the study didn?t even study the link between cancer and EMFs, rather, as designed, at best the ?study? (which didn?t actually study anything at all) was an inventory of cable diameters in selected residential areas. The study didn?t demonstrate correlation, it didn?t demonstrate association and it didn?t demonstrate causation ? but it DID cause a flap and thanks to agenda driven journalists, there are still people in our society that wrongly believe that EMFs from hair dryers, electric blankets, and overhead lines will give you cancer, in spite of a lack of evidence.

I once had to perform a metaanalysis on a disease known as chronic toxic encephalopathy (aka ?organic brain syndrome?). I reviewed scores and scores of and scores of original studies from around the world. To my surprise, in some 80% of the studies, the conclusions of the authors weren?t supported by the data or the study! Frequently, the authors would make one-liner conclusions on issues that their study never addressed.

It still happens today ? look at the flap caused by the bogus, junk science report about the mould Stachybotrys atra and the deaths of children in Ohio (that has now long since been completely discredited and retracted). What upset me the most about that report was that my peers swallowed the goop WITHOUT EVER READING THE ORIGINAL paper, choosing instead to swallow digests of reports or distillations from other sources that reported on the ?findings.? I read the original when it first was published, and immediately discounted it as nonsense and bad science and I said so publically on the AIHA board (which caused a lot of problems for me for almost four years). Eventually, the study was discredited and withdrawn, and the sheep who had bravely attacked me for bad-mouthing the CDC were mow nowhere to be seen.

We still see such silliness to this day such as the ?study? often cited by duct cleaners to ?prove? that cleaning ducts will improve indoor air quality and reduce airborne fungi ( Garrison RA, Robertson LD, Koehn RD, Wynn SR. Effect of heating-ventilation-air conditioning system sanitation on airborne fungal populations in residential environments. Ann Allergy 1993;71:548- 56). In fact, the study absolutely found no such finding, and indeed, taken at face value using the same flawed logic, the ?study? equally demonstrated that if you clean your ducts, certain species of airborne moulds will actually increase. Or the study reported in the journal Environmental Health Perspectives (which seems to almost specialize in requiring authors to include an element of junk science in order to get published) that purported to be the first case conclusively demonstrating that exposure to ordinary concentrations of indoor moulds cause hypersensitivity pneumonitis , when in fact, the ?study? ? which was sloppy, sloppy, sloppy, sloppy ? did no such thing. (Apostolakos M.J., Rossmoore H., and Beckett W.S. Hypersensitivity Pneumonitis from Ordinary Residential Exposures, Environmental Health Perspectives, Volume 109, No.9 Sept 2001).

So when I hear of reports that are reporting about a report of a scientific study that proves that X causes Y,? I yawn a little, and turn to the comics for something a little more credible.

But, those are just my pre-coffee thoughts on a rainy Thursday morning. Whose knows, when I wake up, I may change my mind.

Cheers!
Caoimh?n P. Connell

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG
[/u]


Originally Posted By: jbushart
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Thank you for your educated response.


Each time I consider adding radon testing to the services I offer, I re-read your posts and your web site and I am challenged to find a credible way to market these services in a manner that I am personally comfortable with.

How would you suggest a home inspector present radon testing to the public?


--
Home Inspection Services of Missouri
www.missourihomeinspection.com

"We're NACHI. Get over it."

www.monachi.org

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Hello Mr. Bushart:


?How would you suggest a home inspector present radon testing to the public?? An excellent question. I believe that radon testing can be a valuable part of an home inspector?s tool bag providing a good service. Just follow cook-book EPA protocol to reduce your liability exposure.

Become EPA ?certified? and tow the EPA line and that way, you don?t have to concern yourself with defending the protocols, or the results, you don't have to deal or even care about the validity of the results; you are offering a service according to an established protocol, you are not presenting yourself as an expert, merely a service provider. For my part, as a scientist, I can buck the EPA and their risk assessment model and not get into trouble, but an Home Inspector doesn?t have the same luxury.

Just my thoughts... others may disagree.

Cheers,
Caoimh?n P. Connell

http://www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: bkelly2
This post was automatically imported from our archived forum.



Caoimh?n P. Connell wrote:


For my part, as a scientist, I can buck the EPA and their risk assessment model and not get into trouble, but an Home Inspector doesn?t have the same luxury.

Just my thoughts... others may disagree.

Cheers,
Caoimh?n P. Connell

http://www.forensic-applications.com



Good point about Home Inspectors staying within the EPA guidelines.

You may have a lower likelyhood of getting in trouble. Just because one is a scientist does not exclude one from trouble, or does it?. ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)


--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello

Originally Posted By: dandersen
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Originally Posted By: phinsperger
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Caoimh?n P. Connell wrote:
.....But, those are just my pre-coffee thoughts on a rainy Thursday morning. Whose knows, when I wake up, I may change my mind.]


Mr. Connell,

So I can conclude from this that coffee and rain on Thursdays causes one to change their mind ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)


--
.


Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !

Originally Posted By: jhagarty
This post was automatically imported from our archived forum.



dandersen wrote:


I have personally found that 98% of the "high" Radon Tests I have conducted were directly related to improper construction techniques.



I did not Know that Radon was caused by Incompetent Builders. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)


--
Joseph Hagarty

HouseMaster / Main Line, PA
joseph.hagarty@housemaster.com
www.householdinspector.com

Phone: 610-399-9864
Fax : 610-399-9865

HouseMaster. Home inspections. Done right.

Originally Posted By: dbowers
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- EPA, the American Medical Association, The American Lung Association, the Surgeon General of the United States AND Johnson County, KS where I live call Radon a known carcinogen and with prolonged exposure - the 2nd leading cause of lung cancer in the USA.


Therefore I address it accordingly - call it as such, and could care less what qualified Realtors or others think about it. I would suggest that for liability sake most half-way intelligent home inspectors do the same.


Originally Posted By: phinsperger
This post was automatically imported from our archived forum.



dbowers wrote:
Bottom line - EPA, the American Medical Association, The American Lung Association, the Surgeon General of the United States AND Johnson County, KS ....


Dan,

I agree with you. In fact I am one of very few up here that even offer Radon testing.

However, your statement above indicates that all of the associations named (EPA, AMA, etc) agree. Did each one of them do their own study(s) and independently come to the same conclusion? Or did one of them actually do the study(s) and publish their findings and subsequently the other associations followed along. I suspect the latter but I really don't know. Of course they would all agree if they are all following the same study(s).

Not looking at the conclusion for a moment but rather at the authoritative credibility weight being assigned; "If all these associations say the same thing it must be true". It may very well be. But why do they all say the same thing?

If stated to your clients, realtors, etc in the same way as your post, you might be giving it more weight than it deserves. I'm not attempting to argue with you, just want others to understand how additional credibility can be "generated" by authoritative agencies who may have had nothing to do with the original study(s).

When I discuss radon with a client, I cite both American and Canadian views on it as they are vastly different.


--
.


Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Hello Mr. Bowers ?


That is not the bottom line.

Actually, here's the bottom line:

Although the EPA ?summarized? their findings in their nice little public packets they distribute to the American Public (readable by anyone with a fifth grade education) ?

If one looks at their actual statements in their study, here is what the US EPA really concluded:

Currently there is very little information about...the health effects associated with exposures to radon at levels believed to be commonly encountered by the public. The only human data available for predicting the risks to the public are studies examining the health effects of exposure to radon and its progeny in underground miners. This information would be appropriate for predicting the risks to the public if everyone was a miner, everyone lived in mines, and a large fraction of the general population smoked cigarettes.

(U.S. Department of Energy "Radon- Radon Research Program, FY 1989, DOE/ER-448P., March 1990).

Believe it or not, not every one is a miner. And, personally, I don't live in a mine, and niether do any of your clients (sometimes, my clients appear to be mine dewellers). If you happen to find a market of mine-dwellers in need of home inspections, then the EPA, ALA, AMA estimates (and the silly 4 pCi/l limit) may apply to them ... if they smoke while living in their mine home. Bottom line: The EPA itself admits their estimates are NOT appropriate.

The NRC understood the limitations of the EPA study and concluded...

In summary, a number of sources of uncertainty may substantially affect the committee's risk projections; the magnitude of uncertainty associated with each of these sources cannot readily be quantified. Accordingly, the committee acknowledges that the total uncertainty in it's risk projections is large.

Why were the uncertainties large? Well, let?s look at what the EPA said about their own study. They said:

Exposure in the U.S. cohort is poorly known; cumulative WLM (CWLM) are calculated from measured radon levels for only 10.3 percent of the miners...and guesswork is used for about 53.6 percent of the miners.

Guesswork. Hmmmm?. Very reliable, that guesswork stuff. Especially when more than half of your study hinges on it.

So here?s the bottom line: The EPA, the American Medical Association, The American Lung Association, the Surgeon General of the United States AND Johnson County, KS, have all used EXACTLY the same EPA foundational study based on ?.. TA DA! GUESSWORK!

Now, having said all that ? let?s remember three things 1) It is a common misconception that ?carcinogen? means ?cancer causer;? however, that is not true. Although there are hundreds of compounds that have the classification ?carcinogen,? there are only about 25 to 30 exposures that are known to cause cancer in humans.

2) The largest study to date conducted in this country found a negative correlation between cancer and radon in communities (that is, cancer rates were the lowest in areas that had the highest radon concentrations). There is a reason for that; however beyond that point ? let?s not loose sight of the fact, that even if the EPA guesswork is right, their guesswork merely demonstrated that at it?s VERY, VERY worst, the risk of death from radon is equal to being one pound overweight for every pCi/l over 4 pCi/l ? SPREAD OVER 70 YEARS!

3) I can?t remember my third point. But was good, REALLY, good. When I remember it, I will post again.

Cheers!
Caoimh?n P. Connell
www.forensic-applications.com

p.s. It stopped raining, and I didn't change my mind. So much for causation - but correlation is still in the running!

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: Bill Field
This post was automatically imported from our archived forum.



Dear Mr. Connell,


I have never posted to this message board before, but several home inspectors contacted me after reading some of your posts regarding the health risks of radon and radon progeny. There is a firm scientific base to document that prolonged residential radon (actually radon progeny) exposure causes lung cancer. The EPA estimates that 21,000 lung cancer cases each year are attributable to residential radon exposure. The EPA risk estimates were mainly based on projections from radon-exposed underground miners (see: BEIR VI report [http://www.epa.gov/radon/beirvi.html).

Additional studies are now complete DIRECTLY examining the relationship between residential radon exposure and lung cancer. Both the North American and European pooling of residential radon studies have found that prolonged residential radon exposure even below the EPA?a action level of 4 pCi/L causes an increase in lung cancer (See: Epidemiology. 2005 Mar;16(2):137-45 and BMJ. 2005 Jan 29;330(7485):223).

In reference to Dr. Cohen?s ecologic analyses.

As you may know, the ecologic study design can not be used to assess risk, but merely to generate hypotheses. Numerous examinations of his work, including some by the National Academy of Science, have clearly demonstrated that his findings are most likely due to residential confounding by smoking. In fact, the same inverse association that he notes between lung cancer and radon, is found for other smoking-related cancers (see article by Puskin on this matter).

I feel your posts are a disservice to public health. Residential radon exposure is a serious health threat. I urge you to become more familiar with the literature on radon health effects.

One last note, the WHO expert committee on radon has recently released a statement regarding the health risks of radon progeny exposure; the statement can be found at their site ?
http://www.who.int/ionizing_radiation/env/radon/en/index.html

I do not have time for an extended debate on this issue, but would be happy to respond briefly to any comments or questions you may have.

Regards, Bill Field


R. William Field, M.S, Ph.D.
Associate Professor
College of Public Health
Department of Occupational and Environmental Health
University of Iowa
Iowa City, IA 52242

319-335-4413
bill-field@uiowa.edu


Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Hello Dr. Fields:


?Give me the premise, I?ll argue the facts.?

Whilst it?s true that Bernie?s ecological studies have their flaws, they are nothing compared to the uncertainties associated with the flip-side of the argument ? in any event, how would you explain away the negative correlation of ten standard deviations that Bernie found? (?if memory serves). So long as grossly inappropriate risk models such as the linear-no-threshold dose response model and the one-hit carcinogenesis models currently used are employed, and dose rate, hormesis, and DNA repair mechanisms and selectional bias are ignored, there will be argument ? the authoritative nature or the laudable desires of the researchers? organization notwithstanding.

So why aren?t more appropriate models used? Answer: They don?t give the answers the policy wonks want to see. The fact that you bring up social disservice in my posts underpins the problem that lies in policy disguised as science which appears to be precisely what the EPA stated: ?Sure it?s bad science, but it makes good policy.?

Good heavens! Tautology, tautology, tautology.

That fact that home inspectors are calling and questioning the issues indicates that my posts are doing quite a good service ? and hitting the intended mark. It is interesting that you fear those who question, and associate clarity as disservice.

I would bet you lunch, that based exclusively on your post, I can accurately predict who you voted for in the last presidential election.

Cheers!
Caoimh?n P. Connell
www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: Bill Field
This post was automatically imported from our archived forum.



Mr. Connell,


Residential radon studies do not require linear no threshold extrapolations, so this is not an issue. Regarding Dr. Cohen?s data, even the National Council on Radiation Protection has invalidated his findings. In fact, Dr. Cohen has stated many times that his data can not be used to assess the risk posed by radon. Nonetheless, as the National Council on Radiation Protection points out, ?The clearest data for estimating lung cancer risk from low levels of radon exposure continue to rest with higher-dose studies of miner populations in which projections to zero dose are consistent with estimates arising from most case-control studies regarding residential exposure.?


RESIDENTIAL RADON EXPOSURE AND LUNG CANCER RISK: COMMENTARY ON COHEN'S COUNTY-BASED STUDY.
Health Physics. 87(6):647-655, December 2004.
Heath, C W. Jr *; Bond, P D. +; Hoel, D G. ++; Meinhold, C B. +[S]
National Council on Radiation Protection Summary report - http://www.ncrponline.org/
Abstract:
The large United States county-based study ( Cohen 1995, 2001) in which an inverse relationship has been suggested between residential low-dose radon levels and lung cancer mortality has been reviewed. While this study has been used to evaluate the validity of the linear nonthreshold theory, the grouped nature of its data limits the usefulness of this application. Our assessment of the study's approach, including a reanalysis of its data, also indicates that the likelihood of strong, undetected confounding effects by cigarette smoking, coupled with approximations of data values and uncertainties in accuracy of data sources regarding levels of radon exposure and intensity of smoking, compromises the study's analytic power. The clearest data for estimating lung cancer risk from low levels of radon exposure continue to rest with higher-dose studies of miner populations in which projections to zero dose are consistent with estimates arising from most case-control studies regarding residential exposure.


Health Phys. 2003 Apr;84(4):526-32.
Smoking as a confounder in ecologic correlations of cancer mortality rates with average county radon levels.

Puskin JS.

Office of Radiation and Indoor Air, U.S. EPA, Washington, DC 20460, USA. puskin.jerome@epa.gov

Cohen has reported a negative correlation between lung cancer mortality and average radon levels by county. In this paper, the correlation of U.S. county mortality rates for various types of cancers during the period 1970-1994 with Cohen's radon measurements is examined. In general, quantitatively similar, strongly negative correlations are found for cancers strongly linked to cigarette smoking, weaker negative correlations are found for cancers moderately increased by smoking, whereas no such correlation is found for cancers not linked to smoking. The results indicate that the negative trend previously reported for lung cancer can be largely accounted for by a negative correlation between smoking and radon levels across counties. Hence, the observed ecological correlation provides no substantial evidence for a protective effect of low level radon exposure.


J Radiol Prot. 2002 Jun;22(2):141-8.
The potential for bias in Cohen's ecological analysis of lung cancer and residential radon.

Lubin JH.

Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD 20892-7244, USA. lubinj@mail.nih.gov

Cohen's ecological analysis of US lung cancer mortality rates and mean county radon concentration shows decreasing mortality rates with increasing radon concentration (Cohen 1995 Health Phys. 68 157-74). The results prompted his rejection of the linear-no-threshold (LNT) model for radon and lung cancer. Although several authors have demonstrated that risk patterns in ecological analyses provide no inferential value for assessment of risk to individuals, Cohen advances two arguments in a recent response to Darby and Doll (2000 J. Radiol. Prot. 20 221-2) who suggest Cohen's results are and will always be burdened by the ecological fallacy. Cohen asserts that the ecological fallacy does not apply when testing the LNT model, for which average exposure determines average risk, and that the influence of confounding factors is obviated by the use of large numbers of stratification variables. These assertions are erroneous. Average dose determines average risk only for models which are linear in all covariates, in which case ecological analyses are valid. However, lung cancer risk and radon exposure, while linear in the relative risk, are not linearly related to the scale of absolute risk, and thus Cohen's rejection of the LNT model is based on a false premise of linearity. In addition, it is demonstrated that the deleterious association for radon and lung cancer observed in residential and miner studies is consistent with negative trends from ecological studies, of the type described by Cohen.


Health Phys. 1998 Jul;75(1):11-7.
Residential 222Rn exposure and lung cancer: testing the linear no-threshold theory with ecologic data.

Smith BJ, Field RW, Lynch CF.

College of Medicine, Department of Preventive Medicine and Environmental Health, University of Iowa, Iowa City 52242, USA.

In most rigorous epidemiologic studies, such as case-control and cohort studies, the basic unit of analysis is the individual. Each individual is classified in terms of exposure and disease status. However, in ecologic epidemiologic studies, the unit of analysis is some aggregate group of individuals. Summary measures of exposure and disease frequency are obtained for each aggregate, and the analyses focus on determining whether or not the aggregates with high levels of exposure also display high disease rates. The ecologic study design has major limitations, including ecologic confounding and cross level bias. Cohen has attempted to circumvent these limitations by invoking the linear no-threshold theory of radiation carcinogenesis to derive aggregate "exposures" from individual-level associations. He asserts that, "while an ecologic study cannot determine whether radon causes lung cancer, it can test the validity of a linear-no threshold relationship between them." Cohen compares his testing of the linear no-threshold relationship between radon exposure and lung cancer to the practice of estimating the number of deaths from the person-rem collective dose, dividing the person-rem by the number of individuals in the population to derive the individual average dose, and then determining individual average risk by dividing the number of deaths by the number of individuals in the population. We show that Cohen's erroneous assumptions concerning occupancy rates and smoking effects result in the use of the wrong model to test the linear no-threshold theory. Because of these assumptions, the ecologic confounding and cross level bias associated with Cohen's model invalidate his findings. Furthermore, when more recent Iowa county lung cancer incidence rates are regressed on Cohen's mean radon levels, the reported large negative associations between radon exposure and lung cancer are no longer obtained.



Health Phys. 1998 Jul;75(1):4-10
On the discrepancy between epidemiologic studies in individuals of lung cancer and residential radon and Cohen's ecologic regression.

Lubin JH.

Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA.

There is still substantial confusion in the radiation effects community about the inherent limitations of ecologic analysis. As a result, inordinate attention has been given to the discrepant results of Cohen, in which a negative estimate is observed for the regression of county mortality rates for lung cancer on estimated county radon levels. This paper demonstrates that Cohen's ecologic analysis cannot produce valid inference on the exposure-response relationship for individuals unless lung cancer risk factors (smoking, age, occupation, etc.) for individuals are statistically uncorrelated with indoor radon level within counties or unless risk effects for radon and other factors are additive. Both of these assumptions are contradicted in the literature. Thus, contrary to common assumption, when a linear no-threshold model is the true model for radon risk for individuals, higher average radon concentration for a county does not necessarily imply a higher lung cancer rate for the county. In addition, valid inference from county-level ecologic analysis and the elimination of the ecologic bias cannot be achieved with the addition of county-wide summary variables (including "stratification" variables) to the regression equation. Using hypothetical data for smoking and radon and assuming a true positive association for radon and lung cancer for individuals, the analysis demonstrates that a negative county-level ecologic regression can be induced when correlation coefficients for smoking and radon within county are in the range -0.05 to 0.05. Since adverse effects for radon at low exposures are supported by analysis of miner data (all data and data restricted only to low cumulative exposures), a meta-analysis of indoor radon studies, and molecular and cellular studies, and since ecologic regressions are burdened by severe limitations, the negative results from Cohen's analysis are most likely due to bias and should be rejected.


Originally Posted By: kwilliams
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I feel it is an honor for NACHI that


Mr. Connell and Mr. Field have chosen


the NACHI BB as a venue for a debate


on this subject.



Member - MAB


http://www.nachi.org/convention2006.htm

Originally Posted By: bkelly2
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Mr. Connell & Mr. Field, gentlemen in your opinions what level of radon is safe?



“I used to be disgusted, Now I try to Be amused”-Elvis Costello

Originally Posted By: Bill Field
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Brian,


You asked, ?gentlemen in your opinions what level of radon is safe?? That is an excellent question. It depends on what one considers safe. Risks are all relative. What one person considers safe another person may not. There are also a lot of factors that affect our perception of what is a risk. For example, radon is naturally occurring so there are no villains to blame ? this reduces the risk perception. Because it is invisible and odorless, there are no sensory reminders to make you think about it. Can you imagine if it was purple and coming up through the foundation how many calls you would get?

Radon decays into solid particles that can deposit in your lung. Two of these decay products (polonium-218 and polonium 214) deposit most of the dose to your lung (see: http://www.vh.org/adult/provider/preventivemedicine/Radon/HealthRisk.html). This chapter I wrote some time ago for an occupational medicine book is a bit dated, but provides a general overview of the decay.

Radon decay products deliver over half of the average Americans radiation dose each year. As the radon decay products decay in the lung, they release small burst of energy (called alpha particles) that can damage the DNA. Alpha particles (a type of radiation) are somewhat unique in that they can cause double strand DNA breaks. These double strand DNA breaks are more difficult for the body to repair. Many scientists believe that cancer is monoclonal, which means that even one misrepaired double strand DNA break can initiate the cancer.

So to answer your question, even very low radon exposures HAVE THE POTENTIAL to cause cancer. However, the chances at very low concentrations (less than 1 pCi/L) are extremely low. As compared to other risks, I personally would call exposures less than 1 pCi/L relatively safe. It may be of interest that there are parts of Iowa where the year long outdoor radon concentration is equivalent to the mean U.S. indoor radon concentration (1.5 pCi/L). So part of radon reduction depends on what is really achievable for a particular home.

We also know from the recent North American and European Pooling of Residential Radon Studies that prolonged exposures as low as 3 pCi/L increased the lung cancer risk. In the Iowa Radon Residential Radon Study I was involved with, there was about a 50% increased risk after 15 years exposure at 4 pCi/L (EPA's action level), see: http://www.cheec.uiowa.edu/misc/radon.html

The finding of the Iowa Radon Study was a bit of a surprise to me, I must admit to being skeptical of the ability of radon to cause lung cancer from residential exposure prior to seeing the results of all the studies.

See also, http://www.epa.gov/radon/images/radon_pooling_studies.pdf
http://www.news-medical.net/?id=8389


I understand that NACHI will be offering a two day workshop on radon (presented by RTCA) during the upcoming conference.
http://www.nachi.org/convention2006.htm

Regards, Bill Field

R. William Field, M.S, Ph.D.
Associate Professor
College of Public Health
Department of Occupational and Environmental Health
University of Iowa
Iowa City, IA 52242

319-335-4413
bill-field@uiowa.edu
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