Heavy metals are everywhere in the environment and it’s quite impossible to avoid exposure to them. Even people who are not occupationally exposed carry metals in their body as a result of exposure to other sources such as food, beverages or air.
Some heavy metals are essential nutrients, such as iron, cobalt and zinc. Other heavy metals such as ruthenium, silver and indium are relatively harmless but may be toxic in large amounts or in certain forms. A third group of heavy metals are sources of heavy metal poisoning. These include cadmium, mercury, lead and arsenic, the four most common metals that produce symptoms of heavy metal toxicity.
Common sources of toxic metal exposure
Potential sources of heavy metal poisoning include industrial wastes, agricultural runoff, occupational exposure, mining, paints and treated lumber.