Rocketdyne Worker study

[Gary Schroeder <schroede@mail.sep.bnl.gov>]

Regular readers know that here has been some discussion of the Rocketdyne
worker study on Radsafe recently.  This article, which appeared in
"Occupational Safety & Health", Vol. 27, No. 16., should be of particular
interest.  Many of the  statements contained within should cause a lot of
discussion on this group.

SCIENTISTS SAY REPORT DEMONSTRATES NEED TO STRENGTHEN OCCUPATIONAL EXPOSURE
LIMITS

SIMI VALLEY, CALIF. - A study released September 11 linking cancer deaths
and worker exposure to radiation at a Los Angeles area company once
involved in nuclear power research strengthens a growing body of evidence
indicating regulators should reconsider occupational radiation exposure
limits, scientists unveiling the study's results said.

The government funded investigation was conducted by the [UCLA].  It found
that nine of the facility's workers died from cancers attributable to
externmal radiation exposures of 10 mSv or more.  Another 15 cancer deaths
among the 4,600 workers studied were tied to internal exposure doses at any
level.

This study suggests that the magnitude of the health effects of long-term
exposures to low doses of radiation may be appreciably greater than
previously believed, Hal Morgenstern, a UCLA epidemiologist who headed the
project, said at a conference.

The study showed that the cancer deaths at the Rocketdyne facility were
attributable to doses well below those considered permissable by official
national and international regulatory bodies, Dan Hirsch, co-chairman of
the pamnel and former UCLA researcher, noted.

Another alarming finding is that the excess relative risk of the "low-dose"
radiation was at least six to eight times greater than risk previously
assumed on the basis of atomic bomb survivor data, several members of the
panel added.

Members of the advisory panel that conducted the study said it was
definitley a "wake-up call" for regulators responsible for setting
standards, but it also provides other importnat findings.

A team of scientists hired by the company, Rocketdyne, which was acquired
by the Boeing Co., to review the report immediately refuted the
significance of the study calling the conclusions "overly broad."

COMPANY CALLS FINDINGS TOO BROAD

In a statement, the company said the advisory panel, made up of scientitst,
citizens, and Rocketdyne workers, is overstating the reults of the study.
Michael E. Ginevan, one of Rocketdyne's specialists, also said "Their data
dosen't support their conclusions."

Alice Stewart, a physician and radiation expert from the University of
Birmingham in Great Britain and a member of the panel, said the results
support her reseaqrch indicating that older adults are more at risk from
radiation.

State officials launched the study in 1991 in response to concerns raised
by citizens living near the Santa Susana Field Laboratory of
Rocketdyne/Atomic International, previously owned by Rockwell
International.  The facility once operated 10 nuclear reactors and
conducted tests for the [DOE].

The state decide to focus on worker health because they were the group most
likely to have recieved the highest doses of radiation, and because the
doses were routinely monitored and recorded with the use of film badges.

UCLA researchers analyzed company records for 4,600 Rocketdyne workers who
were monitored for radiation between 1950 and 1993.  The investigators
tracked each worker to determine who had dies, when the death ocurred, and
what caused the death.

WORKERS IDENTIFIED

Of the workers studied, researchers identified 875 who had died; 258 of
those deaths were due to cancer.  The study did not identify workers who
developed cancer but have not died.

According to the study, workers with the highest cumulative doses of
radiation were the most likely to have died from one or more types of cancers.

The follow-up period for the study, 44 years, was one of the longest to
date for any investigation of nuclear workers, allowing researchers to
detect elevated death rates from cancers that had not before been
associated with radiation exposures, UCLA's Morgenstern explained.

Susan J. Knox, a Stanford University professor of radiation oncology hired
by Rocketdyne, said the study was well-done, but "the numbers were very
small and some of the conclusions were questionable."

"The results stand, and they're very strong," David Michaels, a professor
of epidemiology at the City University of New York Medical School and a
member of the state's advisory panel, said.  Michaels added that the entire
advisory panel agreed with the findings.

Rocketdyne officials said it would continue to monitor the group of
workers, as recommended by the researchers.  "We feel that medical
follow-up and continued monitoring of our current and former employees in
the study groupare the most apppropriate next steps," the company said.

Copies of the report are available through the UCLA Public Information
Office, James West Center, Box 951431, Los Angeles, CA 90095-1431.  (310)
825-2585.


=======================
Gary L. Schroeder
Brookhaven National Laboratory
Environmental Protection Office
gs1@bnl.gov