Still Crazy After All These Years: Mercury Cells in the Heart of America

For many decades, the manufacture of polyvinyl chloride (PVC) depended upon a controversial technology invented in the 1890s that polluted the air and water with mercury. Today is World Water Day, and it’s worth noting that some factories still use this toxic technology, and are pouring mercury waste into rivers, lakes and oceans around the world, including in North America.

Chlorine, an essential ingredient of polyvinyl chloride (PVC) plastic is found most readily in brine (very salty water). In the 1890s, two scientists developed a way to electrolyze brine using liquid mercury cathodes in a cell, which produced chlorine and sodium hydroxide.  The elixir of mercury catalyzed the chlorine industry, and the PVC that followed.  By the 1970s, the chlorine industry became the world’s leading consumer of mercury.[1] The release of mercury into water exacted an increasing environmental and human health toll.  

Gradually, in North America, most mercury cells have been replaced with diaphragm[2] and membrane technology. Industry representatives like to say that mercury pollution is a problem of the past. “Neither workers nor the public is exposed to dangerous levels of mercury related to PVC,” insists the Society for the Plastics Industry.[3] The Vinyl Institute asserted recently that there is “no mercury cell chlorine used in PVC manufacture.”[4]

But, with little attention, four chlorine plants in North America continue to run mercury cathode cells. Two plants in the United States and two in Mexico still use this 19^th century technology; three of them do not plan to stop. They are among the 100 chlorine plants in 44 countries that, according to the United Nations, still use mercury cathodes.[5]

PVC’s global mercury toll

Researchers have documented extensive mercury contamination in river and ocean sediments near and downstream from chlorine and vinyl chloride monomer factories that serve the polyvinyl chloride industry.[6] 

Mercury deposited in sediments reacts with microorganisms to form extremely potent neurotoxic organic compounds, especially methylmercury.[7]  Mercury compounds like methylmercury target the nervous system, often with devastating impacts. Symptoms of mercury poisoning include speech difficulties, tingling of the extremities, fatigue, loss of full control of bodily movements, hearing and cognitive loss, hallucinations, coma and death.[8]

Mercury compounds bio-accumulate in fish and other seafood. People who eat highly contaminated fish can suffer mercury poisoning. The most famous case is Minamata Bay, Japan, where a vinyl chloride monomer factory dumped mercury, and contributed to the poisoning of thousands of people in the 1950s, the effects of which continue today.[9]

Hardly a concern of the past, the impacts of the PVC industry’s mercury use continue to grow.  The recent toll from mercury pollution at chlorine, vinyl chloride monomer, and related mercury waste processing plants worldwide, reaches from the state of Tennessee[10] to Cartagena, Columbia,[11] Cato Ridge, South Africa,[12]  Tainan City, Taiwan,[13] and many other places.

Ongoing Mercury Pollution

In the United States alone, according to industry reports to the EPA Toxics Release Inventory, the PVC industry released over 738,107 pounds (369 tons) of mercury and mercury compounds to air, water, and land between 1987 and 2014, including:

• 87,903 pounds of fugitive air emissions of mercury, from plants in Ohio, West Virginia, Louisiana, New York, Alabama, Indiana and Texas.  The two highest releases came from the country’s remaining two operating mercury cell chlorine plants: ASHTA Chemicals in Ashtabula, Ohio and Axiall’s Eagle Natrium plant in Proctor (New Martinsville), W.V.   
• 24,014 pounds of air stack emissions. Again, the highest mercury releases came from the Ashtabula and Proctor plants.
• 3,368 pounds of mercury releases into water.  Axiall’s Proctor plant accounts for almost half of this amount: it reported the release of 1,564 pounds of mercury since 1987.
• 2,330 pounds of mercury releases into on-site facilities, including underground injection wells.
• And, at least 620,492 pounds of mercury waste transfers to off-site disposal facilities, which typically are located in lower-income communities and communities of color.[14]

In 2014, ASHTA Chemicals stated that it is in the process of eliminating its use of mercury cell technology in Ashtabula, but that the transition to membrane cell technology would not be completed until late 2016.[15]  In the meantime, ASHTA projected that it would generate 2,500 pounds of mercury pollution per year through 2016.[16]

Of most concern: Axiall Corporation operates a 57-year-old mercury cell plant, dubbed Natrium, in New Martinsville, West Virginia.[17] As of today, it has no plans to stop. Chip Swearngan, the corporation’s communications head, told the Healthy Building Network that “Axiall has not announced any plans related to its mercury circuit processes at its Natrium facility in West Virginia.”[18]

Instead, plant operators recently petitioned the state of West Virginia, successfully, for a variance, which allows it to measure mercury levels in the Ohio River only after it has been diluted in a “mixing zone.”[19] Since 1987, this facility’s managers reported discharging 1,564 pounds of mercury into the Ohio River, more than any other chlorine plant in the country.[20]

And in Mexico, Industria Quimica del Istmo SA (part of CYDSA S.A.) runs two mercury cell plants,[21] one in Coatzacoalcos, Veracruz, where it has polluted a river with mercury,[22] and the other in the city of Monterrey, just south of Texas. There are no signs that CYDSA plans to decommission either plants’ mercury cells.

From communities bordering these plants, to rivers flowing past these plants to the global atmosphere and wherever mercury-contaminated rain falls, the PVC industry’s ongoing mercury releases reach across the globe, and will last many decades if not centuries. As long as it is uncontained and available in the environment, mercury’s impacts on people and other creatures up the food chain grow over time.[23]

The continuing use of mercury in chlorine production is an act of sheer madness.   Given owners’ tenacious grips on obsolete equipment, voluntary action seems unlikely. In honor of World Water Day, we call for the US and Mexican governments to shut  down these cells.

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