PLUTONIUM
179
6. POTENTIAL FOR HUMAN
EXPOSURE
2001). Maximum
239,240
Pu concentrations of 192 and 8,850 Bq/kg (5.19x10
3
and 2.39x10
5
pCi/kg) have
been reported in composite (0–20 cm) and surface (0–5 cm) soil samples, respectively, collected at a
crater created by an underground nuclear explosions in 1965 along the Shagan River at the STS.
Maximum
239,240
Pu concentration of 2.8 and 3.98 Bq/kg (76 and 108 pCi/kg) have been reported in
composite (0–20 cm) and surface (0–5 cm) soil samples, respectively, from villages near the STS. The
activities in soil from the villages are typical of levels associated with global fallout (Carlsen et al. 2001).
Michel et al. (2002) reported mean concentrations 101 and 4.5 Bq/m
2
(2.8x10
3
and 120 pCi/m
2
), for
239,240
Pu and
238
Pu, respectively, for soil cores collected at seven sites adjacent to the catchment of
Blelham Tarn, a
small lake in Cumbria, United Kingdom. Sediment cores were collected from
14 locations in the lake during March 1997 and mean concentrations of
239,240
Pu and
238
Pu were 183 and
4.5 Bq/m
2
(4.95x10
3
and 120 pCi/m
2
), respectively. Isotopic ratios indicated that the source of these
plutonium isotopes was fallout from atmospheric weapons testing (Michel et al. 2002).
239,240
Pu
concentrations in 96 surface soil samples (0–5 cm) collected from 32 areas in Iran ranged from 0.080 to
0.360 Bq/kg (2.2–9.7 pCi/kg) (Aliabadi et al. 2005). Luksiene et al. (2006) reported
239,240
Pu
concentrations in beach and forest surface soils (0–5 cm) collected in 1996–2001 from the Baltic coastline
in Lithuania ranging from 0.06 to 0.80 and from 0.09 to 0.4 Bq/kg (1.6–22 and 2.4–11 pCi/kg),
respectively. Ivanova et al. (1995) reported concentration ranging from 0.05 to 2.73 Bq/kg (1–
73.8 pCi/kg) for
238
Pu and from 0.37 to 5.04 Bq/kg (10–136 pCi/kg) for
239,240
Pu in surface soils (0–2 cm)
collected in the Bryansk, Orel, and Tula regions of Russia in 1992.
239,240
Pu concentrations in surface (0–5 cm) soil samples collected in 1996 in
the Gomel region of Belarus,
near the Chernobyl nuclear plant, were reported as 3.7 and 0.8 Bq/kg (100 and 20 pCi/kg) dry weight
from Chiepietovitach and Pecki, respectively (Michel et al. 1999). Concentrations of
239,240
Pu in soil
samples from the 5–10 and 10–15 cm depths at Pecki were 0.52 and 0.45 Bq/kg (14 and 12 pCi/kg) dry
weight, respectively. Soil concentrations of
238
Pu were 2.2 and 0.39 Bq/kg (59 and 11 pCi/kg) dry weight
from Chiepietovitach and Pecki, respectively.
238
Pu concentrations in soil samples from the 5–10 and 10–
15 cm depths at Pecki were 0.04 and 0.06 Bq/kg (1 and 2 pCi/kg) dry weight, respectively (Michel et al.
1999).
The Mayak PA, which processed weapons-grade plutonium from 1949 to 1952,
discharged radioactive
wastes into the Techa River. Contamination densities of
239,240
Pu in floodplain soil on the Techa River
showed a decrease from approximately 2 to 4x10-
2
kBq/m
2
(50–1 nCi/m
2
) over a distance of 200 km
starting from Dam 11, which is 30 km from the site of radioactive waste disposal.
239,240
Pu
concentrations
PLUTONIUM
180
6. POTENTIAL FOR HUMAN EXPOSURE
in bottom soil along the river course decreased from approximately 5x10
-2
to 2x10
-2
Bq/kg (1.4–
0.5 nCi/m
2
) over the same distance (Akleyev et al. 2000). Børretzen et al. (2005) reported concentrations
of 1.81x10
6
–2.0x10
6
and 1.22x10
5
–1.35x10
5
mBq/kg (48.9–54.1 and 3.30–3.65 nCi/kg) dry weight for
239
Pu and
240
Pu, respectively in surface soil samples from the Asanov Swamp at Mayak PA, collected on
June 26, 1994.
In 1966, two nuclear weapons were accidentally detonated during a collision of two aircraft in the area of
the village of Palomares, Spain.
239,240
Pu inventories in surface soil ranging from 8 to 57,900 Bq/m
2
(0.2–
1,560 nCi/m
2
) were reported in samples collected in the vicinity of the village of Palomares in October
2001 (Jimenez-Ramos et al. 2006). Concentrations in soil samples from Tabernas, 200 km away from
Palomares, were reported as 0.36 Bq/kg (9.7 pCi/kg) for
239,240
Pu Bq/kg dry weight and <0.48 Bq/kg
(<13 pCi/kg) dry weight for
238
Pu (Rubio Montero and Sanchez 2001).
Concentrations of
239,240
Pu in peat bog samples from the area of the Tomsk-Seversk nuclear facility
(Siberia, Russia) were reported as 0.5, 0.6, and 10.5 Bq/kg (13, 16, and 284 pCi/kg) at depths of surface-
5, 11–13, and 20 cm, respectively; reported
concentrations for
238
Pu were 0.06, 0.01, and 0.34 Bq/kg (1.6,
0.3, and 9.2 pCi/kg), respectively. Concentrations of
239,240
Pu in forest soil samples from this area were
reported as 0.052, 0.055, and 0.054 Bq/kg (1.4, 1.5, and 1.5 pCi/kg) at depths of surface, 3-6, and 32–
40 cm, respectively, while concentrations in samples from an area river bank were 0.050, 0.049, and
0.050 Bq/kg (1.5, 1.4, and 1.5 pCi/kg) at depths of 0–3, 9–12, and 18–21 cm, respectively (Gauthier-
Lafaye et al. 2008).
Yamamoto et al. (2008b) reported
239,240
Pu concentrations ranging from 0.16 to 51.87 Bq/kg (4.3–
1,401 pCi/kg) in 26 soil samples collected in October 2005 from Dolon located 60
km northeast of the
Semipalatinsk Nuclear Test Site in Kazakhstan, an area contaminated mainly by the first USSR nuclear
test on August 29, 1949.
Yoshida et al. (2007) reported a
239,240
Pu soil (0–5 cm) concentration of 59.9 Bq/kg (1,620 pCi/kg) dry
weight at 300 m west from the Nishiyama reservoir Nagasaki Japan. This concentration decreased with
increasing distance for the Nishiyama reservoir. The
239,240
Pu concentration in the surface soil at farther
sampling point was 1.82Bq/kg (49.2 pCi/kg) dry weight, a level within the range with global fallout
plutonium concentrations in surface soil of Japanese forests (0.15–4.31 Bq/kg (3.8–116 pCi/kg, dry
weight) (Yoshida et al. 2007).