Re: Source of cancer data

[hflong@postoffice.pacbell.net]

Dear John,

You are correct, in that "inexperienced" is less accurate than

"selective" to describe epidemiologists who prefer 431 diagnoses in the

1% outlier location of 100,000 deaths for inferences about LNT. Further,

I concede that any selection  may be inadvertent or unconscious. I have

great respect for the investigators involved. We all do rationalize.



However, I expect you to observe and concede that Cohen explicitly states

that his findings cannot prove cause and effect, but that in 70% + of US

homes, radon 1-5 pCi/l in >70%  is associated with less lung cancer

mortality than in those with < 0.5 pCi/l, and that does not fit the

linear, no threshold hypothesis (LNT) - as applied to radon and lung

cancer mortality in those US homes. Otto Raabe expands on the statistics

of this in a recent radsafe posting.



Also, I expect you to concede that Cameron underlines his statement that

cause and effect cannot be proven by the NShipyardWS (10x the size of

Field's Iowa study, also case control) because the total mortality with

an extra  0.5+ rem, like mountain state background radiation, but from

Co60 gamma in 27,000 workers (356,000 person years with 2,200 deaths) was

0.76 that of 32,000 matched workers (425,000 person years) receiving only

usual coast background. This also does not fit LNT.



Cameron and Cohen want a clinical trial that could prove benefit (or

harm).

Think of what it may mean - longevity, surgical mortality, AIDS in

Africa, etc.

Do you, too, want definitive proof - a large, clinical trial? Cameron has

suggested one, better than mine (which would have obscured differences

with the effect of 1 rem yearly from CT for controls as well as

subjects).



John Williams wrote:



> What a joke.  Thay must be inexperienced if they do not believe

> Cohen's findings over Fields?

>

> Do a pubmed search on Lubin.  Do you find him inexperienced also.

> How about Sir Richard Doll?

>

> Jay H. Lubin*

>

> Abstract—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.

>

> Sent by Law  Mail



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