compounds find their way to the environment mainly
through tanning and electroplating industries.
Chromium, essentially exists in two forms namely
Cr(VI) and Cr(III). Cr(III) is proved to be biologically
essential to mammals as it maintains an effective
glucose, lipid and protein metabolism. In contrast,
Cr(VI) is highly toxic as it can diffuse as CrO42-
or HCrO4- through
cell membranes. Major toxic effects of Cr(VI)
are chronic ulcers, dermatitis, corrosive reaction
in nasal septum and local effects in lungs. In
view of the toxic effects, BIS maximum permissible
level of Cr(VI) in drinking water is 0.05 mg/l.