Vinyl chloride draft report didn’t omit info on cancer, children

Jun 23, 2023

CLAIM: The Centers for Disease Control and Prevention removed information from its toxicological profile for vinyl chloride about how dangerous the gas is in regards to children, drinking water and cancer.

AP’S ASSESSMENT: False. While a new toxicological profile released as a draft this month has been reformatted from the prior version, it does not omit such information nor downplay the dangers of vinyl chloride, a review of the documents by The Associated Press and independent experts shows.

THE FACTS: In the weeks following the Feb. 3 freight train derailment in Ohio that prompted officials to intentionally release and burn toxic vinyl chloride from five rail cars, a variety of conspiratorial claims about a government document on the gas have spread on social media.

The prior vinyl chloride toxicological profile was released in 2006, and the CDC's Agency for Toxic Substances and Disease Registry released a draft of an updated edition in February, which some baselessly asserted was suspicious timing. Others went a step further to claim that the new version leaves out unspecified information about how the gas, which is used to make plastic products, impacts children, drinking water and cancer.

"The CDC updated their toxicological profile for vinyl chloride 11 days before the disaster in Ohio," one Twitter user wrote on Saturday in a post that was also shared on Instagram. "In what way, you ask? They took a lot of information out about how dangerous it is, particularly with regard to cancer, drinking water, and children." The user did not specify what exact information they were referring to.

But the posts are misrepresenting the document. A comparison of the new draft with the 2006 version shows that while the new report has been significantly reformatted – with some chapters and subsections changed — both documents contain the same information about children, drinking water and cancer, even if not in the same places. Experts who reviewed the two reports concurred.

"It's just in a different format," said Stephen Roberts, professor emeritus with the University of Florida and former director of the Center for Environmental and Human Toxicology. "There's plenty of information in that profile about how dangerous vinyl chloride is. I don't think that it plays down that aspect at all."

For instance, the new draft omits a two-paragraph subsection titled "How Can Vinyl Chloride Affect Children?" and a brief public health statement that was included in the 2006 version. But the new draft doesn't leave out critical research concerning the dangers of vinyl chloride, and discussion of children's susceptibility to the toxic effects of vinyl chloride are discussed at length elsewhere in the new draft.

Both reports assert that data suggests fetuses, infants and young children are susceptible to the toxic effects of vinyl chloride.

"The new version sort of is a much more tightly summarized exposition, but I didn't see them leaving out any specific studies," said Michael Kleinman, an adjunct professor of environmental and occupational health at the University of California, Irvine. "The takeaway is that children are, you know, a much more susceptible group."

Both the new draft and the older version feature subsections devoted to vinyl chloride's association with cancer, as well as references to the potential for children to be exposed to vinyl chloride through drinking water. Vinyl chloride is associated with increased risk of liver cancer and other cancers, according to the federal government's National Cancer Institute.

"All the information is still in there," Kleinman said. "They haven't really changed the final conclusions."

"I don't think that there was anything egregious in the way they’ve done it," he noted.

The ATSDR is currently seeking public comment on the new draft until May. The new draft updates the 2006 version with the latest information published in scientific literature, Kristen Nordlund, a spokesperson for the CDC, wrote in an email to the AP. The draft profiles undergo independent peer review before they are released for public comment. After the public comment period, the documents undergo additional revisions before final publication.

Nordlund said the agency has been working on the update to the vinyl chloride report over the past year and made it available for public comment on Feb. 9, 2023. The process is "not related to the emergent situation in East Palestine," she wrote.

The vinyl chloride profile is one of many compilations of available information on the health effects of various hazardous substances published by ATSDR. Several other toxicological profiles are also currently available for public comment, including reports on cobalt and hexachlorocyclohexane. All of those draft profiles share the formatting of the new vinyl chloride report. Roberts said it's not uncommon for the agency to overhaul the formatting of the reports to improve their readability.

The ATSDR did recently update its vinyl chloride frequently-asked-questions web page, and the new version omits the question "How can vinyl chloride affect children?" among several others. The section was removed from the web page after Feb. 7, a review of the Internet Archive shows. Other information on the page concerning cancer and drinking water is unchanged, and the page includes a link to the full draft toxicological profile.

Despite the coincidental timing with the Ohio train derailment and the new profile, Roberts noted that producing such reports takes time and resources, and it is not unusual for many years to pass between updates.

"These are a lot of work to do," he said, referring to the reports. "These documents are planned well in advance."

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