A chemical found in the vast majority of flavoured e-cigarettes tested by researchers in a new study has been linked to severe respiratory disease.
The study out of the Harvard T.H. Chan School of Public Health, released Tuesday, tested 51 types of flavoured e-cigarettes and refill liquids, known as e-juice.
"In our study we focused on flavours we feel are appealing to children and younger consumers," the study's lead author Joseph Allen, assistant professor of exposure assessment science, said. "Flavours like Waikiki watermelon, alien blood, cupcake and cotton candy."
The researchers said the flavouring chemical called diacetyl was found in more than 75 per cent of the products tested.
Workers in microwave popcorn processing facilities have been warned in the past about diacetyl, which has been linked to the debilitating respiratory disease bronchiolitis obliterans. The condition is colloquially known as "popcorn lung" because it first appeared in workers who inhaled artificial butter flavour.
"It generally requires a lung transplant," Allen said of bronchiolitis obliterans. "It's an irreversible lung disease."
Allen told CTVNews.ca that the flavouring chemicals found in e-cigarettes can also be found in flavoured alcohol, meats and cheeses and are considered generally safe for consumption.
But he noted that the "exposure pathway" with e-cigarettes is different, since the chemicals are being inhaled, not ingested.
"The issue with the workers (in the popcorn facilities) is that they were inhaling the heated flavouring chemicals," Allen said. "Our concern with flavoured e-cigarettes is the exposure pathway is similar."
Allen said while most health concerns regarding e-cigarettes have focused on nicotine, the effects of the flavouring chemicals have been ignored.
He also noted that out of the 51 e-cigarettes and refill liquids looked at in the study, none of the companies included warnings about the flavouring chemicals and the potential risks on their websites or on the product packaging.
"We don’t see that these warnings are reaching users of e-cigarettes," he said.
Allen noted that there are more than 7,000 e-cigarette flavours on the market in the U.S.
Health Canada has yet to regulate e-cigarettes. As their popularity grows, provinces have implemented their own rules regarding e-cigarettes.
In Ontario, electronic cigarettes are treated the same way as regular cigarettes, meaning they cannot be sold to anyone under 19 years old, their promotion and displays are regulated and they're banned in smoke-free areas.
Ontario, New Brunswick and Nova Scotia have also banned the sale of flavoured tobacco.
