Fourth Quarter 2004
INEEL Quarterly Site Environmental Report
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AGRICULTURAL SAMPLING
Another potential pathway for contaminants to reach humans is
through the food chain. The ESER Program samples multiple agricultural products
and game animals from around the INEEL and Southeast Idaho. Specifically,
milk, wheat, potatoes, garden
lettuce, sheep, big game,
waterfowl, doves, and marmots are sampled.
Milk is sampled throughout the year. Sheep are sampled during the second
quarter. Lettuce and wheat are sampled during the fourth quarter, while potatoes
and waterfowl are collected during the fourth quarter. See
Table A-1, Appendix A, for
more details on agricultural product and wildlife sampling. This section
discusses results from milk, potatoes, large game animals, and waterfowl sampled
during the fourth quarter of 2004. A summary of approximate minimum detectable
concentrations (MDCs) for radiological analyses is provided in
Appendix B. There are no regulatory
standards for radionuclide concentrations in agricultural products or wildlife
tissues.
MILK SAMPLING
| Milk samples were collected weekly
in Idaho Falls and monthly at nine other locations around the INEEL (Figure
12) during the fourth quarter of 2004. All samples were analyzed for gamma
emitting radionuclides. Samples are analyzed for 90Sr during the
second and fourth quarters. Data for weekly and monthly 131I
and 137Cs measurements in milk samples are listed in
Table C-8. No 131I
was detected (measured above the 3s value) in any milk sample during the
fourth quarter. Neither 131I nor 137Cs was detected in
any weekly or monthly milk sample.
Bi-annual 90Sr and tritium concentrations measured in milk are
reported in Table C-9. Two
of four milk samples, collected at Dietrich and Roberts, had detectable
concentrations of 90Sr. The maximum 90Sr result was
(1.17 ± 0.18) pCi/L ([0.043 ± 0.007] Bq/L). This result is below the DCG for
90Sr in drinking water of 100 pCi/L and within the range of
historical results measured at the INEEL and background measurements made by
EPA during the past 10 years in Region 10.
Tritium was detected in four of the five biannual milk samples. The
maximum result, (107.00 ± 26.50) pCi/L ([3.96 ± 0.98] Bq/L), is below the
DCG for tritium in drinking water of 2 x 106 pCi/L and within
historical measurements at the INEEL and background measurements made by EPA
during 1995-2005 in Region 10.
|
 |
|
Figure 12. ESER Program milk sampling
locations.
|
Eleven potato samples were collected from
area growers and from out-of-state locations. All samples were analyzed for
gamma emitting radionuclides and 90Sr. No 137Cs was
measured in any sample. Strontium-90 was detected in two of the samples above
their respective 3s values. The maximum concentration of 90Sr was
from a duplicate sample collected from Taber at (274 ± 75) pCi/kg (dry)
(approximately [10 ± 3] Bq/kg). Strontium-90 was not detected in the other
duplicate sample. This value is within historic concentrations measured in
potatoes collected from farms surrounding the INEEL.
Data for 137Cs and 90Sr
in all potato samples taken during the fourth quarter are listed in
Table C -10 (Appendix C).
Five game animals were sampled during the
fourth quarter of 2004. Four were killed as a result of vehicular collisions on
INEEL roads. The accidents involved two pronghorn antelope and two elk. Samples
were also collected from a whitetail deer killed in Montana by a hunter. Efforts
were made to collect samples of thyroid, liver, and muscle tissue from each
animal, but due to their condition at the time of sampling not all animals
provided all samples. Cesium-137 and 131I data for all big game
samples are listed in Appendix C,
Table C 11.
Each sample collected was analyzed for
gamma-emitting radionuclides. Liver and muscle tissue of all animals had
detectable concentrations of naturally occurring potassium-40. Cesium-137 and
131I were not detected in any of the tissue of any animal.
Six waterfowl were collected during 2004:
Four Coots from the control location of Market Lake and two from the Test
Reactor Area (TRA) sewage treatment lagoon. All were analyzed for gamma emitting
radionuclides with a subset analyzed for 90Sr, 238Pu,
239/240Pu, and 241Am. Concentrations of radionuclides measured
in edible tissues are shown in
Table C-12.
Cesium-137 was detected at concentrations
greater than the 3s value in the muscle tissue of the two Coots collected from
TRA. The maximum concentration was (0.20 ± 0.02) pCi/g ([733 ± 81 Bq/g]). No
other radionuclides were measured above the 3s concentration in any edible
tissue.
Waterfowl hunting is not allowed on the INEEL,
but a maximum potential exposure scenario to humans would be someone collecting
a contaminated duck and immediately consuming all muscle, liver, heart, and
gizzard tissue (average 225 g). The maximum potential dose from eating 225 g (8
oz) of meat from the most contaminated waterfowl collected in 2004 was estimated
to be 0.002 mrem (0.2 mSv). This dose is approximately equal to that estimated
last year and orders of magnitude lower than the estimated dose of 0.89 mrem
calculated in 2002. This is attributed primarily to the fact that the TRA Warm
Waste Pond, containing low levels of radionuclides, is no longer in operation.
This dose is far less than 363 mrem we receive each year from ambient sources
and the 100 mrem per year DOE regulatory dose limit.
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