Table 23. Example of concentrations (g/kg) of ERCs in soil as function of depth
(soil samples collected southeast of TMA-5 mine [EX-256], November 1999).
Chemical
Under mine
1015 cm
510 cm
05 cm
Surface
2,4,6-TNT
873
8
10
<d*
<d
2,4-DNT
5480
150
17
6
52
2-ADNT
3428
207
28
14
48
4-ADNT
2802
163
29
14
41
1,3-DNB
524
<d
<d
<d
<d
*Below detection.
obtained for soil collected under TMA-5 EX-256 for
ated with each mean is larger than the mean in each
2,4,6-TNT, 2,4-DNT, 2-ADNT, 4-ADNT, and 1,3-DNB,
case, however, indicating that the distributions are non-
respectively, when it was sampled in November 1999
normal. Thus, the median values are also presented and
(Table 23). Concentrations rapidly decline for all five
provide a better representative value for these distribu-
chemicals with decreasing depths and 2,4,6-TNT and
tions than the means. The median values for 2,4,6-TNT,
1,3-DNB become undetectable at the surface. Surface
2,4-DNT, 2-ADNT, and 4-ADNT in surface soils near
TMA-5 mines are 4, 16, 17, and 17 g/kg, respectively.
concentrations for 2,4-DNT, 2-ADNT, and 4-ADNT
were 52, 48, and 41 g/kg, respectively, for this
Similarly, we summarized the results of analysis of
example.
surface soils collected near PMA-1A mines (Table 24b).
Because it is the surface soil concentrations that are
Out of 95 samples of surface soil collected near PMA-
relevant for chemical detection of land mines, we sum-
1A mines, 10 had detectable levels of 2,4,6-TNT, 25
marized the results for analyses of surface soils col-
had detectable 2,4-DNT, 27 had detectable 2-ADNT,
lected near TMA-5 and PMA-1A mines (Table 24). Out
and 31 had detectable levels of 4-ADNT. We computed
of 172 samples of surface soil collected near TMA-5
the maximum, mean, standard deviation, and median
mines, 33 had detectable levels of 2,4,6-TNT, 37 had
for each chemical, and, like the results for the TMA-5,
detectable 2,4-DNT, and 48 had detectable levels of 2-
the distributions were non-normal. The median concen-
ADNT and 4-ADNT. Mean concentrations for these
trations for 2,4,6-TNT, 2,4-DNT, 2-ADNT, and 4-
four chemicals varied from 4.2 g/kg for 2,4,6-TNT to
ADNT were 4, 32, 44, and 44 g/kg, respectively. While
62 g/kg for 2-ADNT. The standard deviation associ-
the median value for 2,4,6-TNT was the same as found
Table 24. Statistical analysis of analytical results from surface soils collected
near mines in August 1998 and April, July, November 1999.
Concentration (g/kg)
Chemical
Analyses
Detections
Max.
Mean
Median
a. TMA-5
7.5 9.7
2,4,6-TNT
172
33
43.6
4
34.5 50.4
2,4-DNT
172
37
248*
16
62.0 114
2-ADNT
172
48
685
17
60.0 99.0
4-ADNT
172
48
586
17
b. PMA-1A
4.5 3.1
2,4,6-TNT
95
10
2.4
4
7.7 52.7
2,4-DNT
95
25
227
32
109 143
2-ADNT
95
27
600
44
112 122
4-ADNT
95
31
459
44
*One value of 1610 g/kg was reported for 2,4-DNT, but it was determined to be an outlier.
35
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