Page 48 - Soil Degradation, Conservation and Remediation

1.7 Soil Degradation 33

1.7.1.9 War and Ammunitions

Weapons and ammunitions are a source of soil pollution in regions of confl ict.
Firing ranges often leave soils contaminated with metals from spent bullets. Lead
is the primary soil contaminant of concern in these ranges. The normal operation
of a range can produce lead concentrations of several percent (1 % equals to
−1
−1
10,000 mg kg ; safe level is only 35 mg kg ) in soils adjacent to targets. Soil
samples from a weapon destruction facility in Belgium showed high concentration
of arsenic, copper, and lead. Depleted uranium is an important source of soil pollu-
tion. It is highly toxic and has been used in active combat by the US and UK forces.
This material has as much as 75 % of the strength of enriched uranium; so it brings
lasting health problems with it wherever it is used. Two hundred eighty-six metric

tons of depleted uranium was used during the first Gulf War in 1991. Defoliating
agents were used by the American Army in the Vietnam War. These defoliants con-
tinue to cause death and environmental problems today. Agent Orange contained
dioxin which is one of the most potent chemicals. In Vietnam there are areas where
the levels of dioxins in the soil exceed internationally accepted levels by as much as
one hundred times.

1.7.1.10 Indiscriminate Waste Disposal

Materials that have reached the end of their useful life are called wastes (Hill 2010 ).
Wastes are of various kinds: industrial, municipal, agricultural, domestic, and
nuclear. These wastes are the chief sources of soil pollution (Alloway 1995 ).
Municipal wastes include domestic and kitchen wastes, market wastes, hospital
wastes, livestock and poultry wastes, slaughterhouse wastes, and metals, glass, and
ceramic wastes. Municipal wastes can be biodegradable or nondegradable, recy-
clable materials, or inert. Municipal wastes may contain nonbiodegradable organics
and heavy metals. Sewage sludge is a municipal waste often used as composts in

crop fields because it contains considerable amounts of plant nutrients. But for
heavy metal (Pb, Cd, Zn, etc.) contamination of soil, the use of sewage sludge as a
fertilizer is discouraged. Hospital wastes include general wastes, sharps, non-sharps,
blood, body parts, chemicals, pharmaceuticals, medical devices, and radioactive
materials. Potentially infectious waste includes all waste items that are contami-

nated with or suspected of being contaminated with body fluids. These wastes are
often disposed with municipal wastes in open dumps and on lands (Fig. 1.7 ).

1.7.1.11 Use of Agrochemicals

Agrochemicals include fertilizers, manures, soil conditioners, hormones, and pesti-
cides. Fertilizers and manures introduce some heavy metals such as arsenic, cad-
mium, uranium, and vanadium. Phosphate fertilizers contain considerable amount