Nickel

Nickel is a hard, silvery-white metal that is plentiful in nature. It is found in soil and is emitted from volcanoes. It combines with other metals, such as iron, copper, chromium, and zinc, and forms alloys. Alloys are used to make coins, jewelry, valves and heat exchangers. Most nickel is used to make stainless steel. When combined with elements such as chlorine, sulfur, and oxygen it forms nickel compounds. Nickel compounds are used for nickel plating, to color ceramics, for batteries, and as catalysts. Nickel is found in coal waste and sewage sludge.

Nickel in the Environment
Nickel enters the atmosphere from industries that make or use nickel and its alloys or compounds as well as from oil-burning power plants, coal-burning power plants, and trash incinerators. In the air, it attaches to small particles of dust that settle to the ground or fall to the ground in rain or snow over the course of many days. When nickel is released in industrial wastewater it ends up in soil or sediment where it strongly attaches to particles containing iron or manganese. Nickel does not appear to bioaccumulate in fish or other food animals.

Nickel and Coal
Small amounts of heavy metals can be necessary for health, but too much may cause acute or chronic toxicity (poisoning). Many of the heavy metals released in the mining and burning of coal are environmentally and biologically toxic elements, such as lead, mercury, nickel, tin, cadmium, antimony, and arsenic, as well as radio isotopes of thorium and strontium.

The 1.05 billion tons of coal burned each year in the United States contain 109 tons of mercury, 7884 tons of arsenic, 1167 tons of beryllium, 750 tons of cadmium, 8810 tons of chromium, 9339 tons of nickel, and 2587 tons of selenium. On top of emitting 1.9 billion tons of carbon dioxide each year, coal-fired power plants in the United States also create 120 million tons of toxic coal waste. That means each of the nation's 500 coal-fired power plants produces an average 240,000 tons of toxic waste each year. A power plant that operates for 40 years will leave behind 9.6 million tons of toxic waste. This coal combustion waste (CCW) constitutes the nation's second largest waste stream after municipal solid waste.

Rain falling on coal storage piles and coal ash piles can leach out these heavy metal compounds into ground water or lakes and streams, contaminating drinking water sources.

Nickel in Sewage Sludge
Nickel is commonly found in sewage sludge. In the Targeted National Sewage Sludge Survey, a 2009 study by the U.S. EPA of 84 samples of sewage sludge from around the country, nickel was found in all 84 samples in concentrations ranging for 7.44 and 526 parts per million. In sewage sludge applied to land, the U.S. EPA limits nickel to a concentration of 420 parts per million.

Human Exposure and Health Effects
Humans are most commonly exposed to nickel through dietary sources (including drinking water). Other routes of exposure include skin contact with coins, jewelry, soil, or bath or shower water, or inhalation of air (including cigarette smoke) containing nickel.

Nickel Allergies
About 10-20 percent of the population is sensitive or allergic to nickel. The most common reaction is a skin rash, either at the site of contact or elsewhere. On occasion, nickel may trigger asthma attacks in asthma sufferers who are also sensitive to nickel.

Toxicity
Humans who breathe high levels of nickel have suffered chronic bronchitis and reduced lung function. Those who drank water containing high amounts of nickel suffered stomach aches and "adverse effects" to their blood and kidneys. In animal studies, ingestion of large amounts of nickel has caused lung disease and has affected the stomach, blood, liver, kidneys, immune system, as well as reproduction and development. The U.S. Department of Health and Human Services has determined that nickel metal "may reasonably be anticipated to be a carcinogen" and that nickel compounds are known human carcinogens. The U.S. EPA lists nickel refinery dust and nickel subsulfide as human carcinogens.

Related SourceWatch articles

 * Biosolids
 * Sewage sludge
 * Food Rights Network
 * Heavy metals and coal

External resources

 * World Health Organization, Chemical hazards in drinking-water - nickel