List members, I don't know why a 2+ year old
version of the study was posted. Here is what UNC released
today:
http://www.unc.edu/news/newsserv/research/wing5040700.htm
NEWS SERVICES
210 Pittsboro Street, Campus Box 6210
Chapel
Hill, NC 27599-6210
(919) 962-2091 FAX: (919)
962-2279
www.unc.edu/news/newsserv
NEWS
For
immediate use
April 7, 2000 -- No. 208
Embargoed until 5 p.m.
Sunday, April 9
New study finds multiple
myeloma linked to radiation exposures of nuclear
workers
By DAVID WILLIAMSON
UNC-CH News
Services
CHAPEL HILL -- Increasing exposure to ionizing
radiation boosts the risk of multiple myeloma, a rare but often fatal cancer
of blood-forming tissues, especially among people exposed later in life,
according to a new study of workers at four U.S. Department of Energy
plants.
The study, conducted by University of North Carolina at
Chapel Hill researchers, analyzed radiation exposures among plant employees
and compared them to health records. Older workers with cumulative radiation
doses of five rem or more were almost three-and-a-half times more likely to
die from multiple myeloma than workers at the same plants whose cumulative
exposures were less than one rem.
The current occupational limit for
radiation workers is five rem per year. Average background radiation is
between a tenth and a third of a rem per year depending on what is being
counted, such as radon.
A report on the findings appears in the April
issue of Annals of Epidemiology, a scientific journal. UNC-CH School of
Public Health authors are Dr. Steve Wing, associate professor; Dr. David
Richardson, postdoctoral fellow; Suzanne Wolf, research associate; and
programmer Joy L. Wolf, all of epidemiology, and Drs. Douglas J.
Crawford-Brown, professor, and Gary Mihlan, research assistant, both of
environmental sciences and engineering.
"Workers exposed to
ionizing radiation at older ages appeared to be more sensitive than younger
workers," Wing said. "However, that does not mean that it is safe
for young workers to be exposed to radiation. Exposures during the
child-bearing ages might lead to genetic mutations that could affect
children and future generations."
UNC-CH researchers identified
98 workers who died of multiple myeloma and 391 age-matched controls from a
combined roster of 115,143 people hired before 1979 at the Hanford (Wash.),
Los Alamos National Laboratory (N.M.), Oak Ridge National Laboratory (Tenn.)
and the Savannah River (S.C.) nuclear facilities, he said. Information on
work history, smoking, medical X-rays and exposure to physical and chemical
agents came from personnel, medical, industrial hygiene and health physics
records, including readings from radiation badges known as
dosimeters.
The study included workers who died through 1990 or,
among Hanford employees, through 1986.
Male workers and those hired
before 1948 died of multiple myeloma at about twice the rate of women and
workers hired after 1948, the scientists found. Blacks were almost five
times as likely as whites to have developed the illness, although only five
cases were found among blacks.
The National Institute for
Occupational Safety and Health requested and paid for the study because of
previous reports suggesting a link between exposure to ionizing radiation
and cases of the cancer at the Hanford site, Wing said.
"Our
study, which was the largest ever done on this question in U.S. nuclear
workers, was intended to include more cases of the disease, better
evaluation of radiation doses and measurement of other occupational
exposures not available in the Hanford studies," he
said.
Investigators also tried to determine whether workers exposed
to solvents, metals, welding fumes asbestos and other agents faced increased
risks of multiple myeloma, Wing said. Records of such exposures, however,
were inadequate to enable the scientists to calculate increased risks
accurately.
Because exposures to ionizing radiation were almost
entirely below what government regulations currently allow, the findings
could affect federal occupational exposure standards, the scientist said. He
and his colleagues initially hoped to extend their research to other cancers
of the blood-forming organs but were required by their contract to limit the
study to multiple myeloma.
"One important element of this work
is that it comes at a time when the U.S. Department of Energy is expressing
greater concern for workers’ health and the history of radiation
exposures in the nuclear weapons complex," Wing said.
- 30 -
Note: Wing can be reached at
(919) 966-7416 (w) or 542-4403 (h) or steve_wing@unc.edu.
News
Services Contact: David Williamson, (919) 962-8596, david_williamson@unc.edu.
School
of Public Health Contact: Lisa Katz, (919) 966-7467 or lisa_katz@unc.edu.
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