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, The Updated Meta Analysis of E Cigs & Health Outcomes: Still Critically Flawed Chronic electronic cigarette exposure in mice induces features of COPD in a nicotine dependent manner Thorax Can E Cigarette use be Beneficial to Patients with COPD? Red Vape Electronic Cigarette Use Linked to Higher COPD Risk in US, Study Says