Fourth Quarter 2005
INL 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 INL and Southeast Idaho. Specifically, milk, wheat, potatoes, garden lettuce, sheep, big game, doves, waterfowl, and marmots are sampled. Milk is sampled throughout the year and large game animals are sampled whenever available. Sheep are sampled during the second quarter. Lettuce, wheat and waterfowl are sampled during the third quarter, while potatoes 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, and large game animals sampled during the fourth quarter of 2005.
Milk samples were collected weekly in Idaho Falls at Reed’s Dairy and
monthly at eight other locations around the INL (Figure 12) during the
fourth quarter of 2005. Near the end of the quarter, a new weekly sampling
location was selected north of Idaho Falls in Ucon. All samples were
analyzed for gamma emitting radionuclides. Samples are analyzed for 90Sr
and tritium during the second and fourth quarters.
No manmade gamma-emitting radionuclides were detected in any of the samples for the fourth quarter. Data for 131I and 137Cs in milk samples are listed in Appendix C, Table C-8.
None of the fourth quarter samples contained tritium above the detection
limit. Strontium-90 was measured above the 3s uncertainty level in three of
four samples analyzed. Strontium-90 is related to uptake through the food
chain of historical weapons derived fallout. The maximum level of 90Sr
in milk measured in the Dietrich sample (0.66 ± 0.07 pCi/L) was below the
EPA MCL of 8 pCi/L and the DOE DCG of 1000 pCi/L. Data for tritium and
90Sr in milk samples are listed in
Appendix C, Table C-9.
Eleven potato samples were collected from area growers and from one out-of-state location. All samples were analyzed for gamma emitting radionuclides and 90Sr. The first analysis for 90Sr failed; sufficient sample remained to re-analyze eight of the samples. No 137Cs was measured in any sample. Strontium-90 was detected in three of the samples above their respective 3s values. The maximum concentration of 90Sr was from a sample collected from Arco at 1.05 ± 0.21 pCi/kg. This value is within historic concentrations measured in potatoes collected from farms surrounding the INL.
Data for 137Cs
and 90Sr in all potato samples taken during the fourth quarter
are listed in Table C -10
Two large game animals were sampled during the fourth quarter of 2005. Both (one mule deer and one pronghorn) were killed in the north central portion of the INL in the vicinity of the Naval Reactors Facility. Cesium-137 was detected in the muscle tissue of the pronghorn at a concentration similar to those found in both onsite and offsite game and sheep samples in recent years. Data for 137Cs and 131I in fourth quarter large game samples are listed in Appendix C, Table C-11.
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