Nickel is a very abundant element although it is found primarily in combination with oxygen or sulfur. It is found in all soils and is emitted from volcanoes. In its pure form it is a hard, odorless and tasteless, silvery-white metal that is combined with other metals (such as iron, copper, chromium and zinc) to form mixtures called alloys. Coins, jewelry and other metal items are made from these alloys and the compounds are also used for nickel plating, to color ceramics, to make batteries, and as catalysts in some chemical reactions. 

How You Are Exposed

Exposure can occur by breathing air or smoking tobacco containing nickel. Ingestion of nickel can occur by eating food or drinking water that contains smalls amounts of it. You can also be exposed by simply handling coins or other items made of metals containing nickel. 

How Can Nickel Affect Your Health?

As is probably true in all animals, a small amount of nickel is required to maintain health in humans. The most common adverse health effect of nickel in humans is an allergic reaction. Some people can become sensitive to it when jewelry or other items containing it are in direct contact with the skin and once a person is sensitized to it, any further contact with it will produce a reaction - most commonly a skin rash. In more severe cases, some people have asthma attacks following exposure to nickel.

Breathing in large amounts of nickel, such as has been observed in certain industrial workers, can have deleterious effects on the lungs such as chronic bronchitis and reduced lung function. Inadvertent ingestion of very high levels of nickel in water may result in stomach pain and can affect of the blood and kidneys. It is also probable that nickel and some of its compounds can increase the risk for cancers of the lung and nasal sinus.