The human health effects of acute exposure to high levels of ionizing
radiation are well understood; however, when these irradiations occur at low levels,
there is controversy as to their potential health threat (BEIR V, 1990). For
individuals living in areas where the level of naturally occurring background
radiation is relatively high, the issue of additional exposure to anthropogenically
derived sources of ionizing radiation may be of some concern. This study
investigates the presence of radionuclides in surface soils near a United States
Environmental Protection Agency (EPA) Superfund site near Pocatello, Idaho,
where two phosphorus production facilities have operated for more than fifty years.
It is hypothesized that airborne particulates from these facilities are migrating into a
residential community, and are accumulating in the uppermost soil layers.
Soil samples were collected from seven sites located between 1.3 and 6.7
km along a transect aligned with the prevailing downwind direction. The transect
origin lies at the northern boundary of the Superfund site, and the sites were
selected for their ease of public access. Samples were collected at four different 2.5
cm depths (10 cm total) for each site, and these samples were analyzed for their
gamma emissions. Statistical evaluations of the sample data yielded results of no
significant difference in nuclide concentrations between soil layers, or between
sample sites (��=0.05).
This investigation corroborates the EPA discovery that nuclide
concentrations in surface soils decrease rapidly beyond 1 km from the site
boundary. This study extends the available information regarding the presence of
radionuclides in off-site surface soils by approximately 4 km in the prevailing
downwind direction. Additionally, these data appear to contradict the EPA's
conclusion that no residential exposure is occurring via a surface soil pathway. This
investigation finds that surface soil exposures, at locations such as public parks and
schools, may be occurring from radionuclide concentrations that are as high as 4
times that of published background radiation levels. / Graduation date: 2002
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/30995 |
| Date | 24 April 2002 |
| Creators | Blakeman, Christopher John |
| Contributors | Harding, Anna K. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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