mate the resulting surface soil concentra-
Table 6. Estimates for surface soil concentrations for TNT, RDX,
tions that would result. This was done for
and 2,4-DNT resulting from detonation of PMA-2 land mine.
TNT, RDX, and 2,4-DNT from the mean
TNT
RDX
2,4-DNT
and maximum surface snow concentra-
tions obtained (Table 6). For TNT, the
Average surface concentration (g/m2)
20.8
1.81
0.73
mean was 2.4 g/kg and the maximum
Total contaminated surface area (m2)
381
381
381
was 23 g/kg. For 2,4-DNT, the mean was
Total mass deposited (g)
0.08 g/kg and the maximum was 0.24
7933
689
277
g/kg.
Estimate of mean surface soil concentration
2.4
0.21
0.08
(g/kg)* resulting from detonation
Estimates of surface soil concentrations
resulting from buried mines have recently
Estimate of maximum surface soil concen-
23
1.4
0.24
tration (g/kg)† resulting from detonator
been made by Jenkins et al. (2000). For
2,4,6-TNT, the median surface concentra-
* A soil density of 1.7 g/cm3 and a 0.5-cm depth were used to compute the
tion near TMA-5 and PMA-1A mines was
estimated soil concentrations.
4 g/kg, a value only slightly higher than
† Computed from highest value obtained in surface snow samples.
the estimated mean concentration result-
ing from this mine detonation. The estimate for the
maximum TNT concentration that would result from a
Estimates of the mean initial concentrations of TNT
mine detonation was 23 g/kg, which is considerably
in surface soil resulting from detonation of a land mine
higher than the median surface soil concentration near
were similar in magnitude to those resulting from a
buried mines. The half-life of TNT in the soil, however,
buried mine. The half-life of TNT in surface soil is so
is very short (on the order of a few days) and hence the
short, however, that these concentrations would rapidly
surface concentration of TNT would decline rapidly
decline to insignificant levels in only a few days.
after the detonation (Miyares and Jenkins in prep). This
Because of the large amount of spatial heterogeneity in
is not true for the surface soil near a buried mine where
the distribution, however, there could be a few specific
the TNT has a continuous source from the mine and
locations where a small particle of TNT would be
therefore the rate of removal due to transformation is
located that would persist for some time.
counteracted by the continuing flux from the mine.
The mean surface soil concentration estimates for
For 2,4-DNT, the median soil concentrations near
2,4-DNT from this mine indicate that residues from
TMA-5 and PMA-1A mines were estimated to be 16
detonation are much lower than result from the pres-
and 32 g/kg, respectively (Jenkins et al. 2000). These
ence of a buried land mine and hence, if these results
values are considerably higher than the estimated mean
are typical of mine detonations, would not result in seri-
(0.08 g/kg), or even the maximum (0.24 g/kg), result-
ous interference for sensors using 2,4-DNT as the pri-
ing from the mine detonation. Thus, if the results here
mary signature.
are typical of mine detonations, a mine detonation
should not provide a serious background problem for
LITERATURE CITED
chemical sensors that use 2,4-DNT as the primary signa-
ture for buried mines.
Collins, C.M., and D.J. Calkins (1995) Winter tests
of artillery firing into Eagle River Flats, Fort Richard-
son, Alaska. USA Cold Regions Research and Engi-
CONCLUSIONS
neering Laboratory, Special Report 95-2.
Overall, the results from this experiment demonstrate
Environmental Protection Agency (EPA) (1994) Nitro-
the utility of conducting these types of tests on a clean
aromatics and Nitramines by HPLC. SW-846 Method
snow surface. Residues of TNT and RDX were distrib-
8330, Second Update.
uted heterogeneously on the surface snow, emphasiz-
Environmental Protection Agency (EPA) (1999) Nitro-
ing the need to collect large surface area samples to
aromatics and Nitramines by GC-ECD. SW-846 Method
achieve representativeness. A steel plate was placed
8095, Fourth Update.
under the mine to minimize the amount of soil thrown
George, V., T.F. Jenkins, D.C. Leggett, J.H. Cragin,
out by the blast, but this was not completely effective.
J. Phelan, J. Oxley, and J. Pennington (1999) Progress
Some 2,4-DNT contamination of the snow in the crater
to date on determining the vapor signature of a buried
was apparently caused by propellant from previous
landmine. In Proceedings of the SPIE 13th Annual Inter-
range activities. To mitigate this problem, future experi-
national Symposium on Aerospace/Defense Sensing,
ments should be conducted in midwinter when the sur-
Simulation, and Controls, 59 April, Orlando, Florida,
face soil under the snow is frozen.
Volume 3710, p. 258269.
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