Re: Testimony of Steve Wing to US House of Representatives

[Tom Mohaupt <tom.mohaupt@wright.edu>]

RadSafers:
My comments relating to Dr. Wing's testimony.

> Statement to the Subcommittee on Energy and Environment of the Committee on
>  Science, United States House of Representatives, July 18, 2000
> 
>  Steve Wing, Associate Professor, Department of Epidemiology, School of
> Public
>  Health, University of North Carolina
> 
>   By far the most influential are studies of survivors of
>  the bombings of Hiroshima and Nagasaki that are currently the primary basis
> for cancer risk estimates.  However, the A-bomb studies are flawed due to
> selective survival, poor dose measurement and confounding exposures (4-7).
>  The atomic bombings produced massive immediate casualties as well as delayed
>  deaths due to lingering effects of radiation, infectious epidemics, and the
>  destruction of food, housing, and medical services (8).  Only the
> healthiest survived these conditions, especially among those who are most vulnerable,
> the young and the old.  

It's interesting how he proposes this hypothesis as fact. This arguement
was development as an alternative explanation for the lack of cancers in
the low dose region from H/N bombings. Alice Stewart has used this
arguement extensively.

>  Direct observation from low dose studies.
>  In 1956 Dr. Alice Stewart and colleagues reported in The Lancet that fetal
>  exposures during obstetric x-ray examinations are associated with elevated
>  childhood cancer rates (15).  The fetus is especially sensitive to radiation due
>  to rapid cell division.  Stewart's findings have been replicated in numerous
>  other low dose studies (6, 16-18), and standards for medical practice now
>  dictate that small doses of radiation associated with a single x-ray should
> be avoided during pregnancy.
> 
Dr. Wing fails to mention that prospective studies performs on children
exposed to in utero x-rays and other sources of radiation have failed to
support Dr. Stewart's findings. Also the Oxford Study of Childhood Cancers
(OCSS)predicts that one of every 990 children who are x-rayed in utero will
die of cancer and another will die of leukemia. (1) Applying this forecast
to prospective studies yields far more hypothetical cancers than observed.
For example, Court Brown and Doll (2) followed over 40,000 children who
were x-rayed in utero. They found 9 deaths due to leukemia. The expectation
value from normal incidence is 10.6 deaths from leukemia. Applying Knox's
prediction, Court Brown should have seen 50 deaths from leukemia (i.e. 40
due to x-ray plus 10 from natural incidence). Similar findings are observed
when the OCSS prediction is applied to other prospective studies.   So why
does the Oxford study predict far too many cancers? 

Totter and MacPherson (3)contend that the physician's decision to order an
x-ray was not a random process. They suggest that mothers in the case
population needed far more medical care, including the drugs and x-rays,
than the control mothers. Totter and MacPherson's concerns are supported by
Gilman et al. (4).

(1) Knox, E., Stewart, A., Kneale, G. and Gilman, E., Prenatal Irradiation
and Childhood Cancer, Journal of Radiological Protection, 7 (4) 1987, p.
177-192
(2) Court Brown, W, Doll, R, Incidence of Leukaemia After Exposure to
Diagnostic Radiation In Utero, Brit Med J, 11/26/1960, pp. 1539-1545
(3) Totter, J., MacPherson, H., Do Childhood Cancers Result from Prenatal
X-rays?, Health Phys. 40(4), 1981, pp. 511-524
(4) Gilman, E., Wilson, L., Kneale, G., Waterhouse, J., Childhood cancers
and thier association with prenancy drugs and illnesses.

Tom 

Thomas Mohaupt, M.S., CHP
tom.mohaupt@wright.edu

My opinion based my research of the subject matter. This correspondence may
not reflect the opinion of my employer.
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