Five-Year Study Shows ‘Healthy Worker Effect’ At US Paducah Plant

Five-Year Study Shows ‘Healthy Worker Effect’ At US Paducah Plant

A five-year study into the causes of deaths of workers at
the Paducah Gaseous Diffusion Plant (PGDP) in the US state of Kentucky
shows significantly lower death rates from all causes and cancer in general
when compared to the overall US population.

However, death from lymphatic and bone marrow cancers such as leukemia or
multiple myeloma were slightly above national rates.This result is similar to those reported earlier.

The University of Louisville’s School of Public
Health and Information Sciences, the University of Cincinnati and the
University of Kentucky conducted the study.

Researchers compiled data from employees’ work history, demographic
records and records from the US Social Security Administration, the
National Death Index and individual state departments. They found complete
data for 6,759 of the 6,820 employees who worked at the plant for at least
30 days between September 1952 and December 2009.

Out of those 6,759 people, the researchers identified 1,638 deaths. This
is fewer than the 2,253 deaths that would have been expected in the general
public.

They also found that 461 of the deaths were attributed to cancer, much less than 592, to be expected from comparable sized group in the general public.

Researchers concluded that overall mortality and cancer rates were lower
than the reference population, reflecting a “strong healthy worker effect”.
This effect is well known by epidemiologists. Regular medical check-ups and
better early care for health problems among workers in industries such as
nuclear result in generally better health for these workers compared to the
average population.

PGDP is the only gas-diffusion enrichment facility still operating in the
US. Two other plants existed at Oak Ridge, Tennessee and Piketon, Ohio.
Studies had been conducted for these plants, but none had yet been
conducted for PGDP.

David Tollerud, professor of environmental and occupational health
sciences at the University of Louisville’s School of Public Health and
Information Sciences, said the study addressed lingering concerns about the
health of workers at the plant.

He said: “It is important for occupational health and public health
research to attempt to answer pressing concerns of impacted populations,
and we were able to report that we didn't find unexpectedly high rates of
disease in this workforce.”

Security workers had higher overall death rates than other employees,
while chemical operators had higher death rates from leukemia and multiple
myeloma than the rest of the workers.

The increased number of lymphatic and bone marrow cancer deaths is
consistent with what researchers expected, Mr Tollerud said. “Based on
other studies, these forms of cancer have been linked to low levels of
radiation exposure.”

The Paducah plant was commissioned in 1952 as part of a US government
programme to produce enriched uranium to fuel military reactors and nuclear
weapons.

The plant’s mission changed in the 1960s from enriching uranium for
nuclear weapons to enriching uranium for use in commercial nuclear reactors
to generate electricity. It is owned by the US. Department of Energy and is
leased and operated by the United States Enrichment Corporation, a
subsidiary of USEC Inc.

The study, titled ‘Mortality among PGDP workers,’ was published in the
July 2010 edition of the Journal of Occupational and Environmental Medicine
(www.joem.org).

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