Vaping weed is popular, but there are many unknowns about its safety : NPR How People who Smoke or Vape Cannabis Transport the Chemical Residue into Clean Spaces Thirdhand Smoke Resource Center Second hand smoke, smoke free spaces and the law Ottawa Public Health Cannabis' vapes do you know what you're vaping? FRANK How Long Does THC Stay in Your System Through Vaping Addiction Rehab Toronto How to Know if Your Kid is Vaping Marijuana and What to Do About It Southwest Behavioral & Health Services