Lead absorbs into soil
constituent surface such as clay, hydroxides and organic matter. Excess or
deficiency in lead (Pb) affect both plants and animals. Effect from Excesses
was known to be high in the vicinity of smelters and mine. If quantities of
lead are great enough and or infected into the atmosphere, man stand a
chance/risk of taking in some of these lead either by drinking or from the
atmosphere e.g from additives in fuel, stack remission from metal and mine
industries. Thus affecting the health of mankind.
Zinc is known to be one of
the trace elements that occurred in Nigerian soil (first, 1968). It occurs in
the soil in the form of Zns, ZnSO4 and ZnCl. Deficiency in zinc is marked by
retarded growth, loss of taste and decreased fertility. Thus Excess of zinc
causes muscular stiffness symptoms of irritability. Note that zinc when added
to super-phosphate helps to enhance enzyme activity and good leaf formation.
Copper (Cu)
The chief sources of copper
are soil nutrients, shell fish, oyster, cocoa nuts etc (Edward et al., 1985). Copper occurs in soil in
form of CuO, CuSO4. The deficiency of copper in cereal crops leads
to a marked reduction in grain yield. Note that the amount of Copper needed for
normal functioning varies and depends on the amount of other elements ingested.
Cadmium (Cd)
Cadmium also one of the trace elements that
occurred in Nigerian soils. Its concentration is controlled by absorption and
precipitation. The Extent to which it is associated with soil varies greatly
with type of mineral, and the oxidation state of the system. Cd either as
oxides, sulphides, metallic powder or in soluble farm in carciogenic. Severe
toxic effects of Cd include vomiting, diarrhea, muscular cramps. It also causes
eliciting of the kidney and cancer following inhalation (EPA, Us, 2000).
Arsenic (As)
Arsenic as one of the trace
elements that occurred in Nigeria soils, all have toxic endpoints regardless of
its valence state (EPA, US 2000), and are potentially carcinogenic (First, 1968). The Ancient Greeks
used arsenic for therapeutic purposes. Arsenic has long also been used as
poison. Skin cancer is believed to be related to exposure to arsenic
contaminated sources. Sources of Arsenic include water, medical drugs and food
materials.
Nickel (Ni)
Nickel occurs in
the environment at a very low level. Huans use it as an ingredient of steal and
other metal products. Some foodstuffs naturally contain small amount of nickel.
Nickel uptake boost when people eat large quantities of vegetable from polluted
soils. Smokers have a higher uptake of nickel which has severe effects on human
life. Humans get exposed to nickel by breathing air and drinking water.
In summary, uptake
of too large quantities of nickel has the following consequences:
1.
Higher chances of development
of lung cancer, nose cancer and prostrate cancer.
2.
Sickness and dizziness after
exposure to nickel gas.
3.
Respiratory failure.
4.
Allergic reactions such as skin
rashes.
Also,
high nickel concentration in sandy soils can clearly damage plants and can
diminish growth rate of algae in surface water.