Mossman paper in Health Physics News

[BERNARD L COHEN <blc+@PITT.EDU>]

	My response to the Guest Editorial by Ken Mossman in the June

issue of Health Physics News is given below. Please excuse the brevity

as it was limited to 500 words. It will be in the July issue.



Bernard L. Cohen

Physics Dept.

University of Pittsburgh

Pittsburgh, PA 15260

Tel: (412)624-9245

Fax: (412)624-9163

e-mail: blc@pitt.edu

web site: http://www.phyast.pitt.edu/~blc



The Guest Editorial by Ken Mossman (2003) in your June 2003 issue declares

"the debate is over". It claims that Puskin (2003) demonstrates a serious

error in my test of linear-no threshold theory (LNT) utilizing data for

1600 U.S. counties on lung cancer mortality rate - m, radon level - r, and

smoking prevalence - S.  Puskin fits the data to both

			m = A + B r

                  and        m =  a + b r + c S

and finds that values of B and b are both negative, with b not much

smaller in magnitude than B. This agrees with my findings (fitting with

the BEIR formula) but is discrepant by 25 standard deviations with the LNT

prediction of large positive b. After many years of extensive analysis, I

concluded that this discrepancy indicates failure of LNT.

	However, Puskin makes the very interesting observation that,

applying his treatment to other smoking-related cancers, gives the same

behavior of b. Stating that b cannot be negative for other smoking related

cancers, Puskin (and Mossman) conclude that my S-values are erroneous,

missing a strong negative S-r correlation.

	Mossman references my analysis of the Puskin observation (Cohen

2003), but  ignores its most vital finding, that there is no possible set

of S-values that avoid the anomaly of the Puskin observation. Even a

perfect negative S-r correlation does not give a positive b value for lung

cancer as predicted (by many standard deviations) from LNT, and it makes

radon appear to cause the other smoking-related cancers (b positive for

them).

 Faced with this failure to explain the Puskin observation with erroneous

S-values, I offer the suggestion that Mossman "makes light of", that body

organs exposed to cigarette smoke are also exposed to radiation from

radon. Low level radiation is known to stimulate production of DNA repair

enzymes, to stimulate the immune response, to improve scavenging of free

radicals, etc, all of which are protective against development of cancer.

   On an unrelated matter, Mossman claims that my data, interpreted as a

dose-response relationship, are discrepant with data from case-control

studies. The reference he cites for the latter gives no such data, but my

comparisons with published case-control studies (Cohen 1999) show no such

discrepancy. Moreover, Mossman ignores my frequently emphasized point that

my data cannot be interpreted as a dose-response relationship; they serve

only as a test of LNT.

	Mossman misinterprets my reward offer. It was to seek suggestions,

other than failure of LNT, for explaining my data. Since I had tried

unsuccessfully for several years to find such an explanation, without such

suggestions I could only conclude that LNT fails the test. I therefore

thought I should use every practical means for obtaining such suggestions.







REFERENCES

Cohen, BL. Response to Lubin rejoinder, Health Phys 76:438-439;1999



Cohen, BL. The Puskin observation on smoking as a confounder in ecologic

correlations of cancer mortality rates with average county radon levels,

Submitted to Health Physics (April 2003); also item #15 on web site

www.phyast.pitt.edu/~blc



Mossman, KL. The debate is over: lessons learned from Cohen's ecological

study.         Physics News, June 2003, page 3.



Puskin, JS, Smoking as a confounder in ecological correlations of cancer

mortality rates with average county radon levels. Health Phys

84:526-532;2003





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