Health Risks of Ionizing Radiation: - Clark University

Figure 6-12. Barrels of transuranic waste site on a concrete
pad at the Savannah River Site (Department of Energy,
Office of Environmental Management 1996).
the stomach and lymphopoietic system in addition
to increases in cancers of female genital organs and
bone 19 .
The Mound Facility. The Mound Facility,
located in Miamisburg, Ohio, was established as the
first permanent Atomic Energy Commission facility
for atomic weapons research in 1944. Activities
at the facility included process development,
production engineering, manufacturing surveillance
and evaluation of explosive components for the
nuclear arsenal until its closing in 1989.
A cohort mortality study of Mound workers
was published in 1991 (Wiggs et al. 1991b). SMRs
were low, indicating a healthy worker effect, and
comparisons between workers with more or less than
10 mSv of cumulative dose were not significant due
to small numbers of deaths. Dose-response trends,
however, were significantly positive for leukemia 20 .
Wiggs et al. (1991a) studied mortality in Mound
workers with emphasis on potential exposure to the
Radiation Workers 81
alpha emitter polonium-210 (Po-210). This isotope
was separated from lead and used to generate
neutrons to trigger nuclear reactions. Po-210
activities were conducted at Mound between 1944
and 1972; exposure to Po-210 occurred primarily
through inhalation although ingestion may also have
occurred. This study did not find any significantly
elevated SMRs, although more lung cancers were
observed than expected (SMR 1.19, 0.98-1.43; 82
deaths). The assignment of Po-210 dose estimates
was done retroactively and may have been in error;
no significant dose-response trends were observed.
Mallinckrodt Chemical Works. Mallinckrodt
Chemical Works, in St. Louis, Missouri, processed
uranium ore into pure uranium tetrafluroide metal
between 1943 and 1966. Daily average uranium dust
concentrations were sometimes between 100 and
200 times the maximum allowable concentration of
50 µg/m 3 in some areas of the plant. Dupree-Ellis
et al. (2000) analyzed mortality rates at the facility
and found that, although SMRs were not elevated,
there was a significantly positive dose-response
relationship for kidney cancer (ERR 10.5/Sv; 90%
CI 0.6-57.4). As discussed below, this may have
more to do with the chemical nature of uranium than
with its radiological nature.
Linde Air Products Company Ceramics
Plant. The Linde Air Products Company Ceramics
Plant is located in Buffalo NY and processed
uranium between 1943 and 1949. Workers at the site
were exposed to ionizing radiation as well as a wide
variety of chemicals, and uranium contributed to
both types of exposure. The site’s occupational limit
for lung dose was 150 mSv/year during the time of
operation and the exposure levels often approached
this limit. One intention of Dupree et al. (1987), who
studied the risks of the occupational cohort, was to
test the effectiveness of the limit, and this study
found elevated SMRs for a number of endpoints 21 .
19 Elevated SMRs, with 95% CI and number of deaths, were reported for stomach cancer (1.2, 0.7-1.9, 15 deaths),
lympho-reticulosarcoma (SMR 1.4, 0.6-2.8, 7 deaths), Hodgkin’s disease (1.4, 0.5-3.2, 5 deaths), bone cancer (1.7,
0.2-6.0, 2 deaths) and cancer of female genital organs (1.3, 0.5-2.8, 6 deaths).
20 There were two cases of lymphocytic leukemia (including one CLL case) and two cases of myeloid leukemia in
this cohort. Comparing workers with 50+ mSv to workers with