PLUTONIUM
183
6. POTENTIAL FOR HUMAN
EXPOSURE
reported to range from <1x10
-4
(the detection limit) to <2.8x10
-3
Bq/kg (<2.7x10
-3
–<7.6x10
-2
pCi/kg)
fresh weight in both the control group from west Cumbria 1986 and the study group from Sellafield in
1995. The highest
239,240
Pu concentrations of 1.7x10
4
and 1.2x10
4
Bq/kg (0.46 and 0.32 pCi/kg) fresh
weight were found in 1986 diet surveys, which contained crab (Sellafield) and cockles (west Cumbria)
(Sanchez et al. 1999). Cooper et al. (1992) analyzed food and total diet samples for various radioactive
isotopes that were collected from selected communities in areas of the former Union of the Soviet
Socialist Republic (U.S.S.R.) that were contaminated with fallout from the accident at Chernobyl.
Concentrations of
239,240
Pu in total diet samples ranged from 1.5x10
-3
to 7.0x10
-3
Bq/kg (4.1x10
-3
–
2x10
-2
pCi/kg) dry weight (Cooper et al. 1992).
Twenty Emmental cheese samples were collected from 6 European regions (Allgäu, Germany; Bretagne,
France; Savoie, France; Switzerland; Finland; and Vorarlberg, Austria,) and analyzed for various
radionuclides.
238
Pu and
239,240
Pu concentrations were determined in one sample from each
location,
except Finland, and were found to be less than the detection limit (0.3 Bq/kg [8 pCi/kg]; Froidevaux et al.
2004).
Samples of bottom-feeding fish, white sucker (
Catostomus commersoni), channel catfish (
Ictalurus
punctatus
), and carp (
Cyprinus carpio) were collected along the Rio Grande upstream and downstream of
the Los Alamos National Laboratory (LANL) in September 1997 and analyzed for various radionuclides
(Fresquez et al. 1999b). Mean concentration of
239,240
Pu in samples collected downstream of LANL
ranged from 4.8x10
-5
to 47.5x10
-5
pCi/g (1.8x10
-6
to 1.76x10
-5
Bq/g) in
muscle and bone, and from
27.5x10
-5
to 135.0x10
-5
pCi/g (1.02x10
-5
to 5.00x10
-5
Bq/g) in viscera. In samples collected upstream of
LANL,
239,240
Pu concentrations ranged from 5.5x10
-5
to 33.1x10
-5
pCi/g (2.0x10
-6
to 1.22x10
-5
Bq/g) in
muscle and bone, and a mean concentration of 85.1x10
-5
pCi/g (3.15x10
-5
Bq/g) was determined in
viscera. For most of the
radionuclides, concentrations in fish collected downstream of LANL were not
significantly higher than those in fish collected upstream of LANL (Fresquez et al. 1999b).
Børretzen et al. (2005) reported
239
Pu concentrations of 1,010, 12, 95, and 119 mBq/kg (27.30, 0.32, 2.6,
and 3.22 pCi/kg) wet weight and
240
Pu concentrations reported of 1,150, 4, 6, and 44 Bq/kg (31.1, 0.11,
0.16, and 1.2 pCi/kg) wet weight in mussels, pike bone, pike filet, and roach, respectively,
collected on
June 26, 1994 from a reservoir adjacent to the Asanov Swamp, downstream from the Mayak PA.
Oikawa and Yamamoto (2007) reported
239
Pu and
240
Pu concentrations livers of Surume squid caught
during the fishery season from September–December 2002 in the coastal seawaters off Japan.
PLUTONIUM
184
6. POTENTIAL FOR HUMAN EXPOSURE
Concentrations of
239
Pu and
240
Pu of 1.5–28 mBq/kg (0.041–0.76 pCi/kg) and 1.1–24 mBq/kg (0.030–
0.65 pCi/kg), respectively; these concentrations were several thousand times higher than levels found in
seawater.
Various metals and radionuclides, including
238
Pu and
239,240
Pu, were measured in birds and eggs from
Amchitka and Kiska Islands in the Bering Sea/Northern Pacific Ocean.
238
Pu was not detected over the
minimum detectable activity (MDA) in any samples.
239,240
Pu was only detected above the MDA at
0.31 Bq/kg (8.4 pCi/kg) wet weight in a guillemot composite (Burger and Gochfeld 2007).
Concentrations of
239,240
Pu ranged from 12 to 680 pCi/kg (0.44 –25 Bq/kg) dry weight
in attic dust
collected from communities surrounding the Nevada Test Site in southern Nevada and southern Utah
during the summer 1996 and spring 1997. The activity ratios of radiocesium to plutonium in the dust
samples suggest that the Nevada Test Site had a significant contribution to plutonium levels in this area as
compared to global fallout (Cizdziel et al. 1998).
Plutonium concentrations in vegetation were monitored during 2004 on the Hanford Site.
239,240
Pu was
not detected in vegetation samples collected on the Hanford Site in the 100-N Area and the 300 and
400 Areas (DOE 2005c). An average
239,240
Pu concentration of 0.003 pCi/g (1x10
-4
Bq/g) dry weight, was
reported in vegetation samples collected from the 200 and 600 Areas. A
239,240
Pu concentration of
0.00033 pCi/g (1.2x10
-5
Bq/g) dry weight was reported in vegetation from distant communities.
Average
239,240
Pu concentrations in vegetation samples collected in 1999–2002 in the 100-N Area and the 300 and
400 Areas ranged from 0.0004 to 0.024 and from 0.003 to 0.005 pCi/g (1.5x10
-5
–8.9x10
-4
and 1x10
-4
–
2x10
-4
Bq/g) dry weight and was not detected in the 2003 samples. Average
239,240
Pu concentrations in
vegetation samples collected during 1999–2003 ranged from 0.003 to 0.033 pCi/g (1x10
-4
–1.2x10
-3
Bq/g)
dry weight (DOE 2005c). In 2004, mean
239,240
Pu concentrations of 0.0020, 0.0050, 0.0017, and
0.00022 pCi/g (7x10
-5
, 2x10
-4
, 6.3x10
-5
, and 8.1x10
-6
Bq/g) dry weight were reported in vegetation
samples collected site-wide at the Hanford Site, at the perimeter, at the shoreline of the
Hanford Reach of
the Columbia River, and at a distant site, respectively.
238
Pu was only detected in one of five samples
collected on-site at a concentration of 6.0x10
-6
pCi/g (2x10
-7
Bq/g) dry weight. The results reported for
the 2004 samples were similar to those reported in 1993, 1994, 1998, and 2001 (DOE 2005c).
Akleyev et al. (2000) reported that plutonium concentrations in grass samples from the Asanov Swamps
and dams on the Techa River were estimated to be 7–80 Bq/kg (200–2,200 pCi/kg). Average values for
plutonium concentrations in vegetation from the flood plain section from Dam 11 to
the village of