Third Quarter 2004
INEEL Quarterly Site Environmental Report
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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 third 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, lettuce, wheat, and large game sampled during the third 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 samples were collected weekly
in Idaho Falls and monthly at nine other locations around the INEEL (Figure
11) during the third quarter of 2004. All samples were analyzed for gamma
emitting radionuclides. Samples are analyzed for 90Sr during the
second and fourth quarters.
Data for 131I and 137Cs in milk samples are listed in Table C-7. No 131I was detected (measured above the 3s value) in any milk sample during the third quarter.
Cesium-137 was detected in two milk samples collected at Idaho Falls on
July 14th and on July 28th, 2004. The maximum concentration was 2.22 ± 0.96
pCi/L (0.8 ± 0.4 Bq/L) on July 14th. The detection of 137Cs in
milk around the INEEL at very low concentrations is not unusual and is
indistinguishable from 137Cs levels expected from historical
fallout events (e.g. from nuclear weapons tests and Chernobyl) (EPA 1997).
There are no established limits for 137Cs in milk but, for
comparison, the DOE has set the limit for 137Cs ingestion at
20,000 pCi/L (740.7 Bq/L). The maximum 137Cs concentration
measured in milk during the third quarter, 2004 is well below this limit.
Figure 11. ESER Program milk sampling locations.
In 2004 the ESER Program tested two prototype self-contained lettuce planters at the sampling locations in Atomic City and at the EFS on the INEEL. These locations were relatively remote and had no access to water, requiring that a self-watering system be developed. This prototype method allows for the placement and collection of lettuce at areas previously unavailable to the public (i.e., on the INEEL). The planters are set out in the spring with the lettuce grown from seed. This new method also allows for the accumulation of deposited radionuclides on the plant surface throughout the growth cycle.
Eight lettuce samples and two duplicates were collected from private gardens and the prototype planters. Each sample was analyzed for gamma-emitting radionuclides and 90Sr. No result was measured above the 3s uncertainty value.
Data for 137Cs and 90Sr in all lettuce samples taken during the third quarter are listed in Table C-8 (Appendix C).
A total of 13 wheat samples were collected from local grain elevators. All samples were analyzed for gamma-emitting radionuclides and 90Sr. No man-made radionuclides were positively detected in wheat samples above their 3s levels during 2004. Data for 137Cs and 90Sr in all wheat samples taken during the third quarter are listed in Appendix C, Table C-9.
Three game animals were sampled during the third quarter of 2004. Two were killed as a result of vehicular collisions, the third a two-month old mule deer who expired due to unknown causes. The accidents all involved pronghorn antelope (Antilocapra americana). 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 10.
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 was
detected in the liver and muscle tissue from an antelope sampled on July 8,
2004, and the mule deer fawn muscle tissue. Iodine-131 was not detected in any
of the tissue of any animal.
The concentrations measured in the above samples are within the range of values for samples collected in the past. Likewise, the presence of 137Cs is commonly associated with fallout from past weapons testing and nuclear accidents (i.e., Chernobyl).
Marmots were not collected in 2004.
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