Metals occur in many foods, naturally or as a result of pollution. While trace amounts of some metals are important nutrients, higher quantities and other metals can be highly toxic. The common environmental contaminants of greatest concern in food are the so-called ‘heavy metals’, most notably cadmium, lead and mercury. People may be exposed to small amounts of heavy metals through food, water, air, and commercial products. People can also be exposed in their workplace, as several industries use or produce these metals. Each metal is different at its site where it is found and how it behaves in our bodies. Exposure alone does not mean that it is causing any disease or harm.