Nothing good comes from smoking , and vaping isn't a safe alternative. E cigarettes often contain nicotine and other harmful substances, and studies show that young people who vape are more likely to Heated Tobacco Products, Cigarettes, and E Cigarettes: What's the Difference PMI Science e Cigarettes Safety Not Yet Proven CANSA The Cancer Association of South Africa CANSA The Cancer Association of South Africa Alert! e cigarettes may be as harmful as tobacco smoking, says study E cigarettes can result in 'Popcorn Lung'