Nicotine delivery to users from cigarettes and from different types of e cigarettes Psychopharmacology Springer Nature Link A new study published in Nicotine & Tobacco Research found that those using e cigarettes alone were more than twice as likely to develop COPD than people who didn't use any tobacco products, Electronic nicotine delivery systems (ENDS): A convenient means of smoking? ScienceDirect Vaping Around Children Exposes Less Nicotine Than Smoking Ecigator