Primary+Pollutants+Found+in+Waste+Water

__ Heavy metals __ in the form of ions from factory waste: cadmium, mercury, lead, chromium, nickel, copper and zinc. Nickel and Cadmium come from batteries, lead from paint, leaded petrol and roofing material. Mussels and similar organisms are particularly susceptible to picking up large accumulations of these ions, and so such seafood is often carefully checked before being sold to the public.

__ Pesticides __ such as DDT and fungicides. Found in agricultural areas and DDT is persistent. Pesticides remain in ecosystems for long periods of time, through the processes shown in the diagram-picture to the right.

__ Dioxins __ produced when organic chlorine compounds are not decomposed at high enough temperatures. It accumulates in fat and in the liver. Causes abnormalities in foetuses.

__ PCB’s polychlorinatedbiphenyls __ used in transformers and capacitors. They are persistent – impair learning in children and are carcinogenic.