This week, The American Medical Association (AMA) urged Americans to stop using electronic cigarettes of any sort until scientists have a better handle on the cause of 450 lung illnesses and at least five deaths related to the use of the products.

So-called, “vaping,” the use of the products, has become extremely popular over the last year or so, particularly among teens.

According to reporting by Reuters, The AMA has also called on doctors to inform patients about the dangers of e-cigarettes, including toxins and carcinogens, and swiftly report any suspected cases of lung illness associated with vaping to their state or local health department.

The AMA’s recommendation came on the heels of the Centers for Disease Control asking people to hold off on the use of e-cigarette products while it investigates the cause of the spate of severe lung illnesses and at east 6 deaths associated with vaping.

Many, but not all, of the cases have involved those who used the devices to vaporize oils containing tetrahydrocannabinol (THC), the psychoactive component of cannabis.

CDC officials said some laboratories have identified vitamin E acetate in product samples and are investigating that as a possible cause of the illnesses.

Public health experts have not found any evidence of infectious diseases and believe the lung illnesses are probably associated with a chemical exposure.

Users Head the Warnings

As reported by Reuters, Megan Constantino, 36, from St. Petersburg, Florida, quit vaping six days ago after hearing reports of the illnesses and deaths related to vaping.

“It scared me into quitting,” she said.

Like many users of vaping pens, Constantino picked up the device after quitting cigarette smoking three years ago, and said, “It’s the hardest thing I’ve ever done.”

She added, “I threw the last cartridge away. I took a picture of it and I literally cried.”

Constantino said many people who vape have been “on pins and needles” for the investigation results, and she is concerned that the reports of a link to vaping THC may give people an excuse to ignore the warnings.

Up until these warnings, E-cigarettes were generally thought to be safer than traditional cigarettes, which kill up to half of all lifetime users, but the long-term health effects of vaping are largely unknown.

Meanwhile, Gregory Conley, president of the American Vaping Association, which advocates for cigarette smokers to switch to nicotine-based vaping devices, said the AMA should be “ashamed of themselves for playing politics with people’s health and protecting the profits of drug dealers.”

He criticized the AMA for “fearmongering about nicotine vaping products” while not mentioning “the very real risks of vaping illicit THC products.”