Vaping weed is popular, but there are many unknowns about its safety : NPR Health Problems Caused by Secondhand Smoke Smoking and Tobacco Use CDC Secondhand e cigarette aerosols expose kids to less nicotine than cigarettes, study finds, but can still be risky CNN How secondhand smoke, thirdhand smoke & vaping affects kids Smoking vs. Vaping Weed: Know the Facts Hackensack Meridian Health Secondhand Smoke Vermont Department of Health