Nickel (Ni)

By Caitlion O. Hunter, Esq.

Looking at the flares, smokestacks, and ponds across Cancer Alley, you can see and smell the release of pollution into the air, soil, and water. But beyond what is released at the plant sites, there are additional emissions and pollution from the trains, trucks, and ships that transport the petrochemical and fossil fuel products all over the world. This next set of chemicals in The Community Scientists will focus on pollution that is related to shipping and ports, starting with nickel.

Nickel is best known in the USA as making up our five cent piece. But did you know that a nickel coin is only 25% nickel- the rest is copper! Nickel is often combined with other metals to form alloys; more than 60% of nickel used worldwide goes into the manufacture of stainless steel, an alloy also containing iron and chromium. Batteries are another major industrial use for nickel.

Besides the intended applications for nickel, it is also a major unintended pollutant. Nickel is present in small quantities in crude oil. As oil is refined into different products like gasoline components, diesel, and butane, nickel and other heavy metals begin to concentrate in the remaining tar-like residue. One of the last usable products from oil refining before the material is a sludge is heavy fuel oil (HFO). HFO is as thick as molasses; just like molasses concentrates many of the vitamins and minerals found in sugarcane juice, HFO is high in the metals that are found in crude oil, including nickel, lead, and sulfur. The burning of heavy fuel oil to power ships is a major source of nickel emissions into the atmosphere. 60% of the world’s oceangoing large ships use heavy fuel oil- it is cheap and widely available. HFO contains 3.5% sulfur, which forms the pollutants sulfur dioxide and nitrogen oxide when the oil is burned to power the ship’s engines.

Nickel is carcinogenic in humans, and can cause lung or nasal cancer if nickel dust or particulate matter (PM) is inhaled. Workers in refineries and petrochemical plants can be exposed to the most dangerous form of nickel, nickel carbonyl. Nickel carbonyl is used as a catalyst to speed reactions in plastic, petroleum, and steel plating operations. It can form during shutdown operations in hydrocrackers when the concentration of carbon monoxide (CO) is high and the temperature begins to fall below 400F. Absorption of nickel carbonyl through the skin or by inhalation can be deadly. It is characterized by a distinct odor described as musty and sooty, but this can be hard to detect in an industrial setting.

Nickel is a serious problem in Louisiana. The Marathon Garyville refinery in St. John the Baptist Parish releases more than a pound per day of nickel into the Mississippi River. In 2021, 80 refineries across the country released a combined 10,000 pounds of nickel into our waters. In 2024, across seven parishes of Cancer Alley (West and East Baton Rouge, Iberville, Ascension, St. James, St. John, and St. Charles), total nickel emissions were almost 16,000 pounds into air, water, and soils. A 2025 study of heavy metals in Lake Maurepas found that nickel levels peaked 3 to 4 times higher than safe exposure levels. This is especially concerning given that Air Products proposes massive dredging and drilling operations to construct its CCS wells in Lake Maurepas- this operation would release untold amounts of heavy metals from the lakebed. Keeping the lakebed settled in place is the only way to keep nickel, the legacy of refinery-based pollution, locked in place. But for the long-term heath of communities and the lake, ceasing the refining of fossil fuels will prevent more nickel from entering our waterways.

HOW TO REDUCE YOUR EXPOSURE TO NICKEL:

1.  Eliminating fossil fuels is the best way to reduce nickel pollution. However, shipping presents a difficult problem, as most of the alternatives to HFO like hydrogen, ammonia, and liquified natural gas (LNG) are still derived from fossil fuels, leaving few options for truly green and renewable marine fuel.
2. Some dental hardware uses nickel; however, as nickel allergies are common, there are porcelain and other alternatives. Ask your dentist about using nickel-free hardware.
3. Nickel in jewelry can react with sweat causing nickel salts to be absorbed into the skin. The most common cause for developing a nickel sensitivity is through ear piercing. This is especially important for children, who are at risk for developing a lifelong sensitivity to nickel if they are exposed in their childhood. Look for nickel free earrings; stainless steel contains only a small amount of nickel and is usually appropriate even for people with nickel sensitivities.