Mercury

The metal is biologically non-essential but being used in various industries, it is released in environment from both natural and anthropogenic sources. Man-made sources such as coal combustion, non-ferrous metal production, waste disposal etc. release substantial quantities of mercury resulting in eco-toxicity. The last century witnessed several incidences of mercury poisoning causing death of man and animals in Minamata Bay in Japan, Guatemala, Iraq and Pakistan. Methyl-mercury is the most toxic and stable form of mercury and most avian and mammalian predators at the top of contaminated tropics suffer from this form.