• Nickel: health effects

• Brief introduction

• As we all know, nickel is widely used in many areas in our daily life, for example coins, jewellery, mobile phones, magnets, electronics, glasses and kitchen wares. With its excellent properties, it is of great importance in people's lives. However, for human beings, it may also present significant health hazards. The hazard level depends on the amount of inhalation and the duration of inhalation. For example, it is one of the most common allergenic metals. The following Q&As may give you more information about the effect of nickel on human health.

• How can nickel affect my health?

• Nickel is one of the essential biological elements for human beings. However, it is also one of the most common allergenic metals, and about 10%-20% of people are allergic to nickel ion. More women are sensitive to nickel than men. This difference between men and women is thought to be a result of greater exposure of women to nickel through jewellery and other metal items containing nickel. Once a person is sensitized to nickel, further contact with the metal may cause a reaction. The most common reaction is a skin rash at the site of contact. For some sensitized people, dermatitis (a type of skin rash) may develop in an area of the skin that is away from the site of contact. Some workers exposed to nickel by inhalation can become sensitized and have asthma attacks, but this is rare. People who are sensitive to nickel have reactions when nickel comes into prolonged contact with the skin. Some sensitized individuals react when they eat nickel in food or water or breathe dust containing nickel.
• People who are not sensitive to nickel would have to eat very large amounts of nickel to suffer harmful health effects. Workers who accidentally drank light-green water containing 250 ppm of nickel from a contaminated drinking fountain had stomach aches and suffered adverse effects in their blood (increased red blood cells) and kidneys (increased protein in the urine). This concentration of nickel is more than 100,000 times greater than the amount usually found in drinking water.
• The most serious harmful health effects from exposure to nickel, such as chronic bronchitis, reduced lung function and cancer of the lung and nasal sinus, have occurred in people who have breathed dust containing certain nickel compounds while working in nickel refineries or nickel-processing plants. The levels of nickel in these workplaces were much higher than usual (background) levels in the environment.
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• How might I be exposed to nickel?

• Normally nickel comes into contact with the human through food (the major source), water, air, soil, sediment and some hazardous waste sites--as well as through smoking tobacco. Also some products used in our daily lives contain nickel, including stainless steels and nickel alloys used in jewellery, coins, kitchen wares, mobile phones and some medical artificial body parts. Usually, the nickel content of the above sources is low. You may be exposed to higher levels of nickel if you work in industries that process or use nickel. Exposure of unborn children to nickel occurs through the transfer of nickel from the mother's blood to fetal blood. Likewise, nursing infants are exposed to nickel through the transfer of nickel from the mother's breast milk.
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• How can nickel enter and leave my body?

• Nickel can enter your body by breathing air, drinking water, eating food and wearing jewellery which contains nickel. It depends on the size of the nickel particles, whether the nickel element reaches your lungs and your blood. If the particles are large, they stay in your nose; if the particles are small, they enter deep into your lungs. Some of these nickel particles can leave the lungs with mucus that you spit out or swallow. More nickel will pass into your body through your stomach and intestines if you drink water containing nickel than if you eat food containing the same amount of nickel. A small amount of nickel can enter your bloodstream from skin contact. After nickel gets into your body, it can go to all organs, but it mainly goes to the kidneys. The nickel that gets into your bloodstream leaves in the urine. After nickel is eaten, most of it leaves quickly in the feces, and the small amount that gets into your blood leaves in the urine.

• How can families reduce the risk of exposure to nickel?

• For the whole family, it is better to eat food and drink water with no nickel, and keep away from the nickel industries and plants and similar places .
• Avoid wearing jewellery and some other items containing nickel.
• Visit the doctor to check whether you, your children or other family members have been exposed to substantial amounts of nickel regularly.
• Refrain from smoking.
• Be careful when choosing the kitchen wares.

• What recommendations has the federal government made to protect human health?

• The federal government develops regulations and recommendations to protect public health. Regulations can be enforced by law. The EPA, the Occupational Safety and Health Administration (OSHA), and the Food and Drug Administration (FDA) are some federal agencies that develop regulations for toxic substances. Recommendations provide valuable guidelines to protect public health, but cannot be enforced by law. The Agency for Toxic Substances and Disease Registry (ATSDR) and the National Institute for Occupational Safety and Health (NIOSH) are two federal organizations that develop recommendations for toxic substances.
• Regulations and recommendations can be expressed as "not-to-exceed" levels, that is, levels of a toxic substance in air, water, soil, or food that do not exceed a critical value that is usually based on levels that affect animals; they are then adjusted to levels that will help protect humans. Sometimes these not-to-exceed levels differ among federal organizations because they use different exposure times (an 8-hour working day or a 24-hour day), different animal studies, or other factors.
• Recommendations and regulations are also updated periodically as more information becomes available. For the most current information, check with the federal agency or organization that provides it. Some regulations and recommendations for nickel include the following:
• OSHA has set an enforceable limit of 1.0 mg nickel/m³ for metallic nickel and nickel compounds in workroom air to protect workers during an 8-hour shift over a 40-hour working week. EPA recommends that drinking water levels for nickel should not be more than 0.1 mg per litre.
• Source:http://www.atsdr.cdc.gov/PHS/PHS.asp?id=243&tid=44