Ni economical use are also affected by the

Ni

Nickel naturally occurs in elemental form and used in
mattelergical process of different metals and electrical compound production. (ATSDR
1988, USAF 1990).It is seen that nickel is present as a humans as a trace
element.

Ionic forms of nickel can easily solubelize in water easily
so it is more readily absorbed. It helps in conversion of various chemical forms
by binding to different ligands that are involved in different biochemical processes
that occurs in organism. Water and food are generally the main source of entry of
Nickel inside body. Soluble form of nickel is more toxic to the human health
than that of the insoluble form. (Goyer 1991).

Nickel is released directly into the environment by the
power plants and incinerators. It settles on ground as it is or sometimes with
the raindrop comes to upper layer of soil.It can also mix with water stream and
becomes its part.

Effect of Nickel on organism

It is seen that high concentration of nickel in the soil
can cause damage to the plants and diminish the growth rates of the algae. Microorganisms
that have economical use are also affected by the presence of nickel but there
are some microbial species which can develop resistance against nickel (LENNTECH).
In human although Nickel is essential element but if reaches to high
concentration in body may cause different type of cancer.

Cd.

The
presence of cadmium (Cd) in soils, sediments, and water is a major
environmental concern. Their releases into the environment in large amounts as
an industrial waste.It as a major anthropogenic pollutant.it has high mobility
as have
low affinity towards soil. It competes with and replaces other
functional metals inside cells (Hughes and Poole 1989)

Entry
of Cd into microbes is through energy dependent manganese or magnesium
transport system (Nies and Silver 1989; Perry and Silver
1982).
It competes with and replaces other functional metals inside cells.