On average a computer is 23% plastic, 32% ferrous metals, 18% non-ferrous metals (lead, cadmium, antimony, beryllium, chromium and mercury), 12% electronic boards (gold, palladium, silver and platinum) and 15% glass. Only about 50% of the computer can be recycled, the rest is dumped. The toxicity of the waste is mostly due to the lead, mercury and cadmium – non-recyclable components of a single computer may contain almost 2 kilograms of lead. ...

Mercury and Cadmium are classified as toxic metals, and are persistant pollutants in the environment, that stays in the system and is accumulated through the food chains. The main release of these pollutants are on the west coast of the Caspian Sea, off the coast of Russia and Azerbaijan.