46
P. Lazo et al.
5
4
3
2
1
0
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
S
0.0649394
R-Sq
94.1%
R-Sq(adj)
94.0%
La
Th
Regression
95% CI
95% PI
Fitted Line Plot
Th = 0.00634 + 0.2388 La
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0.5
0.4
0.3
0.2
0.1
0.0
S
0.0441347
R-Sq
77.1%
R-Sq(adj)
76.7%
Th
U
Regression
95% CI
95% PI
Fitted Line Plot
U = 0.00158 + 0.3033 Th
Fig. 3.16 Linear regression plots of Th versus La, and Th versus U
3.4.11 Manganese, Mn
Mn is a naturally occurring element that is found in rock, and water. The Mn content
in earth’s crust is about 1000 mg kg
−1 and the natural “background” levels in soil
ranges from 1 to 4000 mg kg
−1 , dry weight (Howe et al. 2004). Weathering process
is the major sources of Mn in the atmosphere. Ocean spray, forest fires, vegetation,
and volcanic activity are other major natural sources of manganese in the atmosphere
(Schroeder et al. 1987). The major anthropogenic sources of Mn in the air include
P. Lazo et al.
5
4
3
2
1
0
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
S
0.0649394
R-Sq
94.1%
R-Sq(adj)
94.0%
La
Th
Regression
95% CI
95% PI
Fitted Line Plot
Th = 0.00634 + 0.2388 La
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0.5
0.4
0.3
0.2
0.1
0.0
S
0.0441347
R-Sq
77.1%
R-Sq(adj)
76.7%
Th
U
Regression
95% CI
95% PI
Fitted Line Plot
U = 0.00158 + 0.3033 Th
Fig. 3.16 Linear regression plots of Th versus La, and Th versus U
3.4.11 Manganese, Mn
Mn is a naturally occurring element that is found in rock, and water. The Mn content
in earth’s crust is about 1000 mg kg
−1 and the natural “background” levels in soil
ranges from 1 to 4000 mg kg
−1 , dry weight (Howe et al. 2004). Weathering process
is the major sources of Mn in the atmosphere. Ocean spray, forest fires, vegetation,
and volcanic activity are other major natural sources of manganese in the atmosphere
(Schroeder et al. 1987). The major anthropogenic sources of Mn in the air include