The Scientific World Journal / 2012 / Article / Tab 2 / Research Article
Uranium in the Surrounding of San Marcos-Sacramento River Environment (Chihuahua, Mexico) Table 2 Activity concentrations of 238 U and 234 U isotopes and their uncertainty, as well as 234 U/238 U activity ratio, in groundwater samples extracted from wells of Sacramento valley.
Well 238 U (mBq/L)234 U (mBq/L)234 U/238 USampling year 1
6
7
5
0
±
4
5
0
2
7
0
3
0
±
1
0
4
0
4
±
0
.
3
2005 2
6
0
7
0
±
4
0
0
2
1
2
0
0
±
8
4
0
3
.
5
±
0
.
3
2005 3
2
5
0
±
1
.
0
3
1
1
±
1
.
2
1
.
3
±
0
.
0
1
2007 4
2
8
±
0
.
7
1
5
5
±
1
.
6
5
.
5
±
0
.
1
2007 5
1
5
±
0
.
7
8
2
±
1
.
1
5
.
4
±
0
.
3
2007 6
1
0
±
0
.
4
4
4
±
0
.
6
4
.
4
±
0
.
2
2007 7
1
0
±
0
.
4
6
5
±
1
.
0
6
.
5
±
0
.
3
2007 8
3
±
0
.
3
1
7
±
0
.
6
5
.
7
±
0
.
6
2007 9
6
±
0
.
4
3
2
±
0
.
7
5
.
3
±
0
.
4
2007 10
6
±
0
.
4
5
3
±
0
.
9
8
.
8
±
0
.
6
2007 11
4
1
±
0
.
8
1
7
0
±
1
.
6
4
.
1
±
0
.
1
2007 12
5
1
±
0
.
9
1
7
5
±
1
.
6
3
.
4
±
0
.
1
2007 13
1
2
±
0
.
5
6
8
±
0
.
9
5
.
5
±
0
.
2
2007 14
1
0
±
0
.
4
6
1
±
1
.
0
6
.
1
±
0
.
3
2007 15
1
3
±
0
.
5
7
1
±
1
.
0
5
.
5
±
0
.
2
2007 16
6
±
0
.
4
4
5
±
0
.
8
7
.
5
±
0
.
5
2007 17
9
±
0
.
4
3
1
±
0
.
7
3
.
4
±
0
.
2
2007
