Wisconsin health officials also said that patients reported using open tank systems and units with replaceable cartridges. Open systems allow users to connect their own bridges of steam liquids, if they wish.
Dr. Emily Chapman, chief medical officer for Children's Hospital in Minnesota, said in the past month it had treated four cases of acute, severe lung injury – including respiratory failure – in teens who had guns. Although the hospital's patients have each shown improvements, Dr. Chapman, it is not clear if they will fully recover.
She also noted that examining a teen's vaping pattern can be difficult.
Dr. Chapman also said she was worried about how much of the public thinks vaping is safe.
"The truth is that we have so little experience of vaping, relative to the experience we have with cigarettes and cigars. Remember how long it took us to find out that cigarettes were linked to lung cancer. There's so much we don't know. ”
A new study by Yale and Duke identified chemicals called acetals in some Juul-e cigarette liquids. These chemicals, the researchers said, can be particularly irritating to the lungs and can cause inhalation damage.
Juul disagreed with the study's conclusions.
"The researchers' hypothetical exposure analysis failed to take into account real-world conditions, including realistic human exposure to vapor products such as Juul," said Lindsay Andrews, a Juul spokeswoman.
Christmas protection contains high levels of nicotine, which can Some experts worry about the effects of nicotine on the brain of a developing teenager, and some studies have suggested that taking nicotine can also affect the heart and arteries.