Nickel

Nickel is a toxic element and should never be trusted. except in small amounts, because it is essential to have some nickel intake.
Humans may be exposed to nickel by breathing air, drinking water, eating food or smoking cigarettes. Skin contact with nickel-contaminated soil or water may also result in nickel exposure. In small quantities nickel is essential, but when the uptake is too high it can be a danger to human health.

An uptake of too large quantities of nickel has the following consequences:
- Higher chances of development of lung cancer, nose cancer, larynx cancer and prostate cancer
- Sickness and dizziness after exposure to nickel gas
- Lung embolism
- Respiratory failure
- Birth defects
- Asthma and chronic bronchitis
- Allergic reactions such as skin rashes, mainly from jewelry
- Heart disorders

Read more: http://www.lenntech.com/periodic/elements/ni.htm#ixzz2E4PXGBLZ

Nickel is used in many products some of you may use everyday including electric guitar strings, magnets and rechargeable batteries. The magnetic properties of nickel actually make it very important for use in computer hard drives.

http://wanttoknowit.com/uses-of-nickel/