News reports inaccurately suggested vinyl chloride could cause cancer of the liver, lungs, and brain
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Figure: train derailment, vinyl chloride, East Palestine, Ohio, PVC, butyl acrylate, ethylhexyl acrylate, ethylene glycol monobutyl ether, phosgene, dioxins, cancer, cancer risk, hepatic fibrosis, cirrhosis, hepatocellular carcinoma, Raynaud's phenomenon
FigureIt looked like Armageddon had come to East Palestine, OH, a small town of roughly 5000 people located about 50 miles northwest of Pittsburgh.
Thirty-eight cars of a 150-car, two-mile long train derailed in early February, some carrying hazardous materials. The most concerning was vinyl chloride, which is used to manufacture polyvinyl chloride, a polymer used to make pipes and flooring.
Vinyl chloride is extremely flammable, and authorities were worried a catastrophic explosion could launch shrapnel over the surrounding area, so they set off a controlled release and burn of the escaping gas. We've all seen pictures of the apocalyptic black cloud that loomed ominously over the town during the burn.
Vinyl chloride is widely used in the plastics industry, and it is transported by rail in pressurized tankers that pass through small towns and large cities every day. In fact, an incident similar to the one in East Palestine occurred late in 2012 when a train derailment in Paulsboro, NJ, leaked 23,000 gallons of vinyl chloride into the environment. Press coverage was sparse because the area was still recovering from the devastation caused by Hurricane Sandy.
The derailment and controlled burn in Ohio exposed people in the surrounding area to a witches' brew of chemical pollutants in addition to vinyl chloride, including butyl acrylate, ethylhexyl acrylate, and ethylene glycol monobutyl ether, plus products of combustion such as phosgene and dioxins.
Cancer Risk
Many news stories suggested that vinyl chloride has been shown to cause cancer of the liver, lungs, and brain, as well as leukemia and lymphoma. This is not accurate.
Vinyl chloride is indeed a known carcinogen linked to cases of hepatic angiosarcoma, a rare and aggressive liver cancer that originates in cells lining the hepatic blood vessels. Only several hundred cases occur in the United States each year, the vast majority of which are idiopathic or attributable to other toxic exposures such as arsenic, radium, or androgenic steroids, according to the National Cancer Institute. (Feb. 27, 2019; http://bit.ly/3JAgElx.)
Hepatic angiosarcoma occurs only after continual, decades-long inhalational exposure to vinyl chloride. I am not aware of any convincing evidence that vinyl chloride causes other types of cancer, including primary hepatocellular carcinoma. It can cause hepatic fibrosis, but it does not seem to lead to actual cirrhosis, a known precursor to hepatocellular carcinoma.
Mild Effects
The acute effects of exposure to vinyl chloride are generally mild. It is an irritant that causes eye discomfort, skin rashes, sore throat, coughing, and headache, all of which were reported by people around East Palestine after the derailment and controlled burn. These symptoms tend to resolve when exposure stops, but they can persist.
Remarkably, I could find no scientific survey of possible chronic symptoms or medical problems in people exposed to vinyl chloride after the 2012 New Jersey derailment.
Vinyl chloride can cause changes in the hands that mimic scleroderma and Raynaud's disease. Just as vinyl chloride or its toxic metabolite chloroethylene oxide can attack the endothelial cells of hepatic blood vessels, ultimately resulting in hepatic angiosarcoma, they can also damage arterial vessels in the hands leading to ischemia and bony resorption of the distal phalanges. (Hint for toxicology fellows: If you are presented with a hand x-ray showing lytic lesions in bones at the fingertips and are asked to identify the exposure on the board certification exam, the answer is vinyl chloride.)
This finding—acro-osteolysis—can be accompanied by other manifestations similar to those of collagen vascular diseases, including Raynaud's phenomenon (painful stiff fingers that turn pale when exposed to cold temperatures) and thickened skin or nodules on the hands and forearms. These changes occur from occupational exposure to high levels of vinyl chloride and are rarely seen today.
Significant exposure to vinyl chloride occurs much less commonly now than in decades past. The chemical was used as a propellant in consumer products such as hairspray until it was banned by the Consumer Product Safety Commission in 1974.
Occupational exposure was markedly reduced following tightened regulation of the chemical industry, but the accident in East Palestine reminds us that vinyl chloride is still around and remains a threat.
It is important to know what, if any, chronic medical problems result from the acute exposure in Ohio. I hope a rigorous program is set up to monitor the population.
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Dr. Gussowis a voluntary attending physician at the John H. Stroger Hospital of Cook County in Chicago, an assistant professor of emergency medicine at Rush Medical College, a consultant to the Illinois Poison Center, and a lecturer in emergency medicine at the University of Illinois Medical Center in Chicago. Follow him on Twitter@poisonreview, and read his past columns athttp://bit.ly/EMN-ToxRounds.
