Re: New Steve Wing Study

["Otto G. Raabe" <ograabe@ucdavis.edu>]

February 3, 1998
Davis, CA

Dear All:

Yesterday Steve Epperson posted the abstract of a new study by Steve Wing
about risks to radiation workers. Dr. Wing is an epidemiologist at North
Carolina who personally believes that the nuclear industry is evil. 

In the 1970's it was noted by Gilbert et al. (Rad. Res. 79:122-128, 1979)
that there was an apparent association of some extra cases of multiple
myeloma among radiation workers at Hanford. This was considered a random
observation, since it was not found in other studies. Also, remember that
if you look at every possible type of cancer, ignore those that are lower
in exposed groups, and look only for those that are elevated, it is
possible that you will find at least one type of cancer that seems to be
associated with radiation exposure. That observation is expected by pure
chance. Then if you ignore everything else, you could claim that this
random observation proves that radiation is responsible even at the low
levels of exposure received by radiation workers. This the the method used
by some epidemilogists who really want something to report.

Okay. What Wing did was get money from NIOSH to study myeloma cases at
Hanford but incorporating data from other laboratories including LANL, ORNL
and SRS. In his abstract he notes that there also were confounding
exposures of the radiation workers to many other agents "including
solvents, metals, welding fumes, asbestos,....and non-ionizing radiation."
However, only exposures to ionizing radiation were quantified well enough
for him to include in his analysis!

This was a case control study where all the cases of myeloma deaths were
matched with control persons who lived to the same age, but did not develop
myeloma. When radiation exposure was considered he found: "Total cumulative
radiation doses were similar between cases and controls." NO RADIATION
EFFECT! Well, that wasn't the right answer, so now he started subdividing
the data and found that if he only considered people whose exposures
occurred at ages 45 or older, there was a significant association of risk
of myeloma with radiation exposure after age 45 "adjusted for age, race,
sex, facility, period of hire, birth cohort, monitoring for internal
radionuclide contamination, and external radiation received prior to age
45." This observation is the whole basis of his report. He reports an
increased incidence of a factor of 4.3 for workers receiving doses greater
than 5 rem. [Review of the A-bomb survivor data shows a dose of above 100
rem delivered instantaneously was required to yield this large an increase
in multiple myeloma cases and simultaneously yielded about a seven-fold
increase in leukemia cases (BEIR V).]

Wing claims that increased cancer sensitivity in older workers is expected
theoretically and found in some other studies. Actually, my reading of BEIR
V shows a consistent reduction in risk of radiation induced cancer of all
types with increased age at exposure! Also, if this is a radiation effect
rather than a chance observation, we would expect that other cancer types
would be more readily observed, such as leukemia and lung cancer, but
apparently not.

Wing's results show no overall effect until selectively grouped to achieve
an observed level of significance. You can guess that he tried every
conceivable combination of age grouping to harvest a significant
observation from the study so that he could declare that his "findings and
other studies of nuclear workers have implications for radiation protection
standards for workers and the general public."

Finally, the observations by Wing that there is no overall effect, but one
remarkably appears when considering exposures of people older than 45,
suggests that there must be a protective effect for exposures that occur at
ages younger than 45. This is because overall he found that: "Total
cumulative radiation doses were similar between cases and controls." NO NET
EFFECT!

Otto  
		*****************************************************
		Prof. Otto G. Raabe, Ph.D., CHP
                [President, Health Physics Society, 1997-1998]
		Institute of Toxicology & Environmental Health (ITEH)
		     (Street address: Old Davis Road)
		University of California, Davis, CA 95616
		Phone: 530-752-7754  FAX: 530-758-6140 [NEW AREA CODE]
		E-mail ograabe@ucdavis.edu