Cadmium
Like lead and mercury, cadmium is also non-essential biologically. The industrial use of cadmium in plastic production, electroplating and manufacture of alloys and batteries is eventually responsible for its release into environment. The dust and wastewater from smelting and refining, phosphate rocks, fertilizers, coal and oils also contribute to discharge nearly 30,000 tons cadmium into environment per year from human activities. Application of phosphatic fertilizers and sewage sludge and other organic wastes to agricultural land increases cadmium concentration in soil, which in turn elevates levels in different trophics of food web. Several reports demonstrate increasing concentration of cadmium in liver and kidneys of wild small mammals viz bank voles, wood mouse, short tailed field voles, common shrew, meadow voles and European voles from contaminated habitats.