Opposing views on e-cigarettes, witnesses interrupting members of Congress and even a wink. A hearing Tuesday on the epidemic of respiratory injuries linked to vaping was one unusual show.

Since the spring, hundreds of reports have surfaced about severe lung injuries associated with vaping and using e-cigarettes. The Centers for Disease Control and Prevention has identified at least 530 cases, including at least seven deaths, and states have reported two others.

In recent weeks, as the news crept wider into the headlines, it galvanized state and federal public health officials to warn people against vaping until the crisis is better understood.

Yet even these rising numbers and stark warnings didn’t unify the often-contentious party lines at the House subcommittee hearing on vaping. Ostensibly about public health, the hearing grew tense and political at unexpected moments.

Witnesses included experts from the CDC, the American Lung Association and Illinois Department of Public Health. Also testifying was Ruby Johnson, of New Lenox, Ill., whose daughter, 19, was hospitalized for a week and spent time in the ICU with a mysterious vaping-related lung injury, causing her to miss her first week of college. It is unclear whether she will have permanent damage.

Committee Republicans called a witness who painted a very different picture. Vicki Porter, a 51-year-old former smoker and current vaper from Lake Mills, Wis., insisted vaping is the thing that allowed her to break her 23-year cigarette habit. She unsuccessfully tried multiple Food and Drug Administration-approved smoking cessation drugs and devices.

Expert witnesses were clear that vapes and e-cigarettes are not acceptable or approved ways to quit smoking traditional cigarettes.

“Switching is not quitting,” said Dr. Albert Rizzo, the chief medical officer at the American Lung Association.

Porter, a vocal vaping advocate on the state level in Wisconsin, pushed back on this assertion, often contradicting the public health experts who testified before her. She said millions of people like her had quit cigarettes thanks to vapes.

“Vaping is a health miracle to me,” Porter said.

In Porter’s opening statement, she said that e-cigarettes were much safer than traditional ones, and that all available evidence said lung injuries had “nothing to do with nicotine vapor products and everything to do with illicit and adulterated street drugs, notably oil-based THC products.” THC is the psychoactive chemical in marijuana.

The panel’s chairman, Rep. Raja Krishnamoorthi (D-Ill.), stepped in to fact-check some of Porter’s statements, saying the FDA did not agree that vaping was safe or even safer than cigarettes. He also pointed to the testimony of Dr. Anne Schuchat, the principal deputy director at the CDC. Schuchat said repeatedly that her organization had no idea exactly what is causing the vaping-related lung injuries and couldn’t point to either THC or nicotine liquids as a culprit.

“May I respond?” Porter asked.

“No,” Krishnamoorthi answered.

Porter also cited a public health finding from the United Kingdom, which said vaping was safer than smoking. Krishnamoorthi later called this a “bogus study” influenced by the vaping industry.

When Rizzo, of the American Lung Association, said there were more than 7,000 toxins present in cigarettes, Porter interrupted and disputed his claim.

“I know this because I smoked and decided to learn about it,” she said.

Porter also interrupted Rep. Ayanna Pressley (D-Mass.), who was questioning another witness. Pressley cited a statistic that for every adult who quits smoking from vapes, 81 children start using nicotine because of them.

“That’s an impossible statistic,” Porter interjected.

In a highly unusual exchange, Porter was accused by Rep. Rashida Tlaib (D-Mich.) of winking at Rep. Glenn Grothman (R-Wis.). Porter explained that she and Grothman were friends, and he had introduced her to the committee earlier at the hearing; she was simply saying hi.

Porter had been asked to testify by Republican committee staffers who knew her because she had worked with Grothman on pro-vaping legislation when he was a state senator.

Partisanship again flared when Rep. Ro Khanna (D-Calif.) brought up President Donald Trump’s proposed ban on flavored vaping liquids, which public health advocates say draw kids and teens into nicotine addiction.

“Washington is a very political place, and now you have the president’s advisers telling him that this is going to hurt his reelection in battleground states because there are hundreds of thousands of people in battleground states who vape,” he said.

Khanna could be referring to a campaign from the right-leaning Americans for Tax Reform, which says vaping bans could cost the president his reelection.

While Democrats brought up youth vaping, calling it an epidemic, Republicans like Grothman and Rep. Jim Jordan (R-Ohio) wanted to focus the hearing on marijuana vaping and the harm of adulterated or counterfeit products.

Jordan asserted that the real epidemic was youth marijuana use, and both he and Grothman wondered aloud if all the instances of vaping injury were actually due to THC instead of regular nicotine vaping.

Schuchat was careful to say that the CDC was classifying the outbreak as vaping-related injuries, not illnesses, because the condition was not responding to antibiotics and clearly was not an infection. She said the culprit could be the nicotine found in regular vaping liquids, the THC found in marijuana vaping products, or something else entirely, like the additives common to both kinds of vaping supplies.

At one point, Rep. James Comer (R-Ky.) brought out two bottles of CBD products, the non-psychoactive ingredient in hemp and marijuana plants only tangentially related to the issue at hand, and talked about how well Kentucky was doing in the hemp-growing business. He said this was an example of an area that needed some regulation to avoid bad actors.

Yet Grothman asked witnesses on both panels if it was possible that all injuries were related to THC, and people were simply reluctant to admit they had been using an illegal substance.

“Over time, more states are legalizing marijuana,” Grothman said. “I wish you’d look into that.”

By Rachel Bluth, Kaiser Health News. Kaiser Health News (KHN) is a national health policy news service. It is an editorially independent program of the Henry J. Kaiser Family Foundation which is not affiliated with Kaiser Permanente.