An illustration shows a man exhaling smoke from an electronic cigarette in Washington, DC on October 2, 2018. - In just three years, the electronic cigarette manufacturer Juul has swallowed the American market with its vaporettes in the shape of a USB key. Its success represents a public health dilemma for health authorities in the United States and elsewhere. (Photo by EVA HAMBACH / AFP) (Photo credit should read EVA HAMBACH/AFP via Getty Images)