**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**