Amidst the debris..

nitroglycerin (NG), nitroguanidine (NQ), nitrocellulose (NC), 2,4-dinitrotoluene (DNT), and
various perchlorate formulations are employed in missile, rocket, and gun propellants 159 .
Whether solid, liquid or vaporised, these substances have the potential to lead to environmental
contamination and may negatively affect human health depending on dose, duration and route
of exposure. Little data is available on the extent of contamination in conflict settings, particularly
in areas that may see intensive use of munitions and where populations may come into contact
with residues.
METALS
Unlike organic contaminants, metals do not break down in the environment, although they may
be able to move through it, depending on local conditions and the metal in question. Metals
generally adhere to soil or partially dissolve in water, where they may be transported to deeper
layers, and can end up in biota. Hg is the only metal which volatilises in elemental form at room
temperature, other metals are not volatilized, unless methylated/alkylated. Because they do not
break down in the environment, heavy metal contamination can result in long-term risks for public
health and the environment as a whole.
EXPLOSIVE SUBSTANCES
Explosive substances undergo varying types of chemical and biochemical transformation,
depending on the compounds involved and environmental and microbial conditions, this
makes predicting their environmental fate and subsequent health risks complex. Most
explosive compounds are relatively persistent in the environment, particularly NC. TNT may
be transformed by sunlight or microbial action into compounds more toxic than itself. The
majority of the particulate explosives are not very mobile in the environment, and absorbed
materials provide an ongoing source of groundwater contamination 160 . RDX, HMX and
perchlorate appear to be common groundwater contaminants; while TNT is generally not.
The aqueous solubility of HMX is low and it tends to accumulate on the surface while TNT
dissolves. NG is rather mobile in soil, in part due to its high solubility (1,250 to 1,950 mg/L).
TNT, RDX, HMX, NG, 2,4-DNT, and 2,6-DNT do not readily volatilise in the aqueous phase,
therefore volatilisation of energetic compounds is negligible 161 . Particulate explosives adsorbed
to soil particles may be spread over a wide area as wind-blown dust 162 . The degradation of
explosives is affected by many factors, such as the presence of oxygen, light and microorganisms.
For nitramines that end up in the environment, such as RDX and HMX, the half-life is generally
hundreds of days 163 .
As a recognised problem around ranges or manufacturing and disposal facilities, efforts
to predict the risk munitions residues may pose have generated a complex debate over
dose-effect relationships, human exposure pathways, mixture toxicology and environmental
behaviour 164 . Decades of civilian and military research into the health hazards associated
with firing, manufacture and disposal have demonstrated that long-term consequences for
humans and the environment are feasible.
Many of the heavy metals, energetic compounds, and some of their decomposition products,
such as DNTs and amino-DNTs that have been used in the Syrian conflict have been proven
to be carcinogenic, genotoxic or mutagenic. Acute or chronic exposure to some has also
been associated with respiratory problems, skins problems, or other detrimental effects on
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