Vapor from flavored e-cigarettes, even those without nicotine, can cause lung cells to die, an Australian study has found.
Scientists from the University of Adelaide and the Royal Adelaide Hospital examined the toxicity of three brands of apple-flavored vaping liquid - with and without nicotine - on healthy lung cells.
They found that the vapor could trigger the death of healthy airway epithelial cells even in products without nicotine. These line the respiratory system and are important for keeping the lungs and airways clean.
They also showed, for the first time, that extracts of the vapor interfered with the immune system by altering the functioning of macrophages, the cells that lock away dead and dying cells in our bodies.
The researchers say the findings, published in journal Respirology, show e-cigarettes shouldn't be considered harmless.
"E-cigarettes should be treated with caution by users, especially those who are non-smokers," the authors wrote.
Dr Miranda Ween, from the Royal Adelaide Hospital, said that regulation was urgently needed.
"There are no regulations on the manufacturing of E-liquids. There are also no requirements to list the ingredients or their quantities."
"As such, no two 'apple', 'chocolate' or 'cotton candy' E-liquids will be made with the same flavoring ingredients or even concentrations. These are the things that we know can affect how unsafe a particular E-liquid is,'' she said.
Australian Medical Association Queensland president Dr Dilip Dhupelia said companies were marketing the product in a way that could cost lives.
"If we don't stop this now, we will have the same epidemic as they are currently experiencing in the US, at great cost to our already overstretched health system in Queensland,'' he said.
The study comes as an eighth death in the US was attributed to e-cigarettes and the Centers for Disease Control and Prevention l(CDC) last week said 530 confirmed and probable cases have been reported in 38 states and one US territory, up from 380 just a week ago.
Federal and state health officials continue to search for what has caused the illnesses. Most patients report using THC, the compound in marijuana that produces a high. Some have used both nicotine and THC, while other patients say they only vaped nicotine.
