A mysterious lung illness that appears to be associated with vaping has swept across the country over the past few months, according to the United States Centres for Disease Control and Prevention. Most of the victims are young people, who have been admitted to hospitals with symptoms that can include severe shortness of breath, fever, vomiting and diarrhoea. One patient in Illinois died. NBC News reports that data from state health departments indicates at least 329 people have been affected.

Many of the cases seem to involve vaped liquids that contain ingredients from cannabis, such as THC (marijuana's psychoactive compound) or the cannabidiol known as CBD. Last Friday, the federal health authorities issued a warning specifically citing vaping products that contain THC or CBD.