EH-92-1 Mortality and Occupational Exposure to Ionizing Radiation
                 OFFICE OF EPIDEMIOLOGY AND HEALTH SURVEILLANCE
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                              HEALTH BULLETIN
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U.S. DEPARTMENT OF ENERGY                                 WASHINGTON, D.C.
Issue 92-1                                                       June 1992
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        Mortality and Occupational Exposure to Ionizing Radiation


A report by Dr. G. M. Kendall and coworkers entitled Mortality and
Occupational Exposure to Ionizing Radiation was published in the
British Medical Journal on January 25, 1992.  The purpose of this
study was to determine if there was an increased rate of death from
cancer in approximately 95,000 British radiation workers who had
been employed at any of several major nuclear sites in the United
Kingdom. 

During their employment at these nuclear sites, most of the workers
had received total radiation doses that were very low, less than 10
mSv (1 rem).  For comparison, the average person who does not work
in radiation-related industries receives about the same amount of
radiation from the natural environment in about 40 months.  Only a
small fraction of these workers (about 9 percent) had received a
total dose that was higher than 100 mSv (10 rem).

This study found that the death rate for all causes combined was
lower for these workers than for the general population of England. 
These results are consistent with other studies showing that worker
populations tend to have lower mortality rates than the general
population because workers must be healthy to be hired, and must
remain healthy to continue their employment.

Among the British radiation workers, the death rate for all types
of cancer combined was lower than expected.  Death rates for lung
cancer and most kinds of leukemia were lower than those for the
general population; however, the death rate for thyroid cancer was
twice as high as expected.  The authors compared cancer death rates
among workers with different radiation doses in order to determine
if workers with a higher total radiation dose also had a higher
rate of cancer.  The rate of death for all kinds of cancer combined
tended to increase slightly with increasing total dose.  The death
rates for leukemia (excluding chronic lymphatic leukemia) and for
multiple myeloma increased with increasing total dose.  Leukemia
and multiple myeloma are two types of cancer that start in the bone
marrow.  No other types of cancer, such as lung and thyroid, were
associated with radiation dosage.

The findings of this study are largely negative; however, the study
had several limitations.  For example, the group of workers being
studied was very young (about half were less than age 45), and the
followup period was fairly short (less than 15 years) for many of
the workers.  These factors are considered important because some
types of cancer do not show up until many years after a person has
been exposed.  Another limitation is that the study did not take
into account any other occupational exposures (for example, toxic
metals or chemicals) or lifestyle factors that might have an
influence on the death rates of these workers. 


      This Health Bulletin is one in a series of routine publications
      prepared by the Office of Epidemiology and Health Surveillance to
      share information from epidemiologic studies throughout the
      Department of Energy complex; however, the authors conclusions do
      not necessarily reflect those of the Department.



For more information contact:  Dr. Terry L. Thomas, Director, Health
Coordination and Communication Division, Office of Epidemiology and Health
Surveillance, U.S. Department of Energy, Washington, D.C.  20585;
Telephone FTS or Commercial (301) 903-5328.
.