PLUTONIUM
173
6. POTENTIAL FOR HUMAN
EXPOSURE
weapons plant, were all <1x10
-5
pCi/m
3
(<4x10
-7
Bq/m
3
) (DOE 2005d, 2005e, 2005f, 2006a).
239,240
Pu
concentrations in airborne particulate matter collected during the first and second quarters of 2005 at
RFETS from an industrial area were 8.3x10
-5
and 1.2x10
-4
pCi/m
3
(3.1 x10
-6
and 4.4 x10
-6
Bq/m
3
),
respectively.
Aerosol particulate samples were collected at three sites (On Site, Near Field, and Cactus Field) near the
Waste Isolation Pilot Plant (WIPP), a deep underground nuclear waste-storage facility near Carlsbad,
New Mexico (Arimoto et al. 2005). The On Site sampling location was 0.1 km downwind of the WIPP
exhaust shaft. The Near Field station was 1 km downwind of WIPP. The Cactus Field station was 19 km
upwind of the WIPP, and served as a reference background site.
Concentrations of
241
Pu were below the
minimum detection limit (1.2x10
-6
Bq/m
3
[3.2x10
-5
pCi/m
3
]) for all 204 samples collected.
238
Pu was
detected above the minimum detection limit (3.9x10
-9
Bq/m
3
[1.1x10
-7
pCi/m
3
]) in 6 of the 204 samples.
239,240
Pu was detected above the minimum detection limit (2.6x10
-9
Bq/m
3
[7x10
-8
pCi/m
3
]) in 203 of the
204 samples. Mean concentrations of
239,240
Pu in the 10 µm particulate matter fraction were 1.1x10
-8
and
8.1x10
-9
Bq/m
3
(3.0x10
-7
and 2.2x10
-7
pCi/m
3
) at the Cactus Flats and Near Field
stations, respectively.
Mean concentrations of
239,240
Pu in the total suspended particulate were 1.8x10
-8
, 1.3x10
-8
, and 1.4x10
-8
Bq/m
3
(4.9x10
-7
, 3.5x10
-7
, and 3.8x10
-7
pCi/m
3
) at the Cactus Flats, Near Field, and On Site stations,
respectively (Arimoto et al. 2005).
Lehto et al. (2006) determined radionuclide concentrations from air sampler filters collected in the town
of Kurchatov and the city of Astana in Kazakhstan. Kurchatov is near the former Semipalatinsk nuclear
test site, which is highly contaminated from nuclear explosions carried out from 1949 to 1989. Astana is
about 500 km west of Kurchatov. Median concentration of 1x10
-7
and 3.4x10
-8
Bq/m
3
(2.7x10
-6
and
9.2x10
-7
pCi/m
3
) for
239,240
Pu and
238
Pu, respectively, were reported in weekly air samples (25,000 m
3
volume) collected during 2000–2001 in Kuchatov. Median concentrations of 2.9x10
-8
and 9x10
-9
Bq/m
3
(7.8x10
-7
and 2.4x10
-7
pCi/m
3
) for
239,240
Pu and
238
Pu, respectively, were reported in air samples collected
during a 3-month period in 2001 in Astana;
238
Pu activity was below the detection limit
in half of the
filters (Lehto et al. 2006).
Hölgye (2008) reported
239,240
Pu and
238
Pu concentrations in air collected from 1997 to 2006 in Prague,
Czechoslovakia of 0.53–5.06 and <0.16–1.10 nBq/m
3
(1.4x10
-8
–1.7x10
-7
and <4.3x10
-9
–3.0x10
-8
pCi/m
3
),
respectively.
239,240
Pu concentrations in Prague post-Chernobyl air samples taken in April 29–May 5,
1986 were 10–28Bq/m
3
(2.7x10
-4
–7.6x10
-4
pCi/m
3
).
PLUTONIUM
174
6. POTENTIAL FOR HUMAN EXPOSURE
6.4.2
Water
Hirose and Aoyama (2003) used the HAM database, a comprehensive data set of various anthropogenic
radionuclides, to calculate background levels of
239,240
Pu concentrations surface waters
of the Pacific
Ocean. In this study, the authors divided the Pacific Ocean basin into 12 “boxes”, which take into
account the analyses of latitudinal and longitudinal distributions of anthropogenic radionuclides. Based
on their analysis,
239,240
Pu concentrations ranged from 6x10
-7
to 2.7x10
-6
Bq/L (2x10
-5
–7.3x10
-5
pCi/L)
within the 12 “boxes”.
Seawater samples collected in 1999 in various regions of the southern Baltic
Sea were analyzed for
plutonium (Struminska and Skwarzec 2004). The highest concentrations of plutonium were generally
found in the dissolved fractions of seawater, and ranged from 1.5x10
-6
to 1.45x10
-4
Bq/L (4.1x10
-5
–
3.92x10
-3
pCi/L) for
238
Pu in samples from Gdansk Bay seaport and
239,240
Pu in samples from Pomeranian
Bay, respectively. The lowest plutonium concentrations were found in the colloidal fractions.
238
Pu and
239,240
Pu concentrations in the colloidal fractions were generally ≤1x10
-6
Bq/L (2.7x10
-5
pCi/L)
(Struminska and Skwarzec 2004). Hirose and Aoyama (2002) reported that the
239,240
Pu particulate
concentrations in surface waters of the western North Pacific Ocean ranged from 3x10
-8
to 3x10
-7
Bq/L
(8x10
-7
–8x10
-6
pCi/L) during 1987–1997. Ahier and Tracy (1995) reported
239,240
Pu water concentrations
in
Lake Michigan, Huron, Erie, and Ontario of 4.4x10
-7
, 4.8x10
-7
, 1.8x10
-7
, and 1.7x10
-7
Bq/L (1.1x10
-5
,
1.3x10
-5
, 4.8x10
-6
, and 4.6x10
-6
pCi/L), respectively.
Hirose et al. (2007) reported
239,240
Pu concentrations in surface waters collected during 2003–2004 from
the South Pacific Ocean mid-latitude region (32.5°S) ranging from 0.5 to 4.1 mBq/m
3
(0.01–1.1 pCi/m
3
).
Yamada and Zheng (2008) reported
239,240
Pu surface water concentrations in samples taken in the vicinity
of the nuclear fuel reprocessing plant at Rokkasho, Japan of 7.6 and 7.8 mBq/m
3
(0.20 and 0.21 pCi/m
3
)
on sampling dates September, 1991 and June 1993, respectively.
239,240
Pu concentrations in surface water
collected at sites along the Japan Sea coast sampled in June, 2003 were 4.9 and 5.9 mBq/m
3
(0.13 and
0.16 pCi/m
3
) at Sado Island and at Ajigasawa, respectively. Yamada et al. (2007) reported
239,240
Pu
concentrations of 13.4, 20.7, 37.2, 26.8, 39.6, 20.6, and 19.2 mBq/m
3
(0.362, 0.559, 1.01, 0.724, 1.07,
0.557, and 0.519 pCi/m
3
) at depths of 0, 150, 250, 600, 900, 1,200, and 1,490 m, respectively,
in samples
from Sagami Bay, Japan, western Northwest Pacific Ocean collected on March 23, 1992.
During 2004, water samples from the Columbia River were collected at Priest Rapids Dam, the most
upstream dam from the Hanford Site, and from Richland, Washington, on the Hanford Site.
Average