We don't know the effects, but we can be pretty confident on the floor. Meaning we know the minimum amount of harm nicotine in vaping is definitely causing, but

We don't know the effects, but we can be pretty confident on the floor. Meaning we know the minimum amount of harm nicotine in vaping is definitely causing, but we aren't sure how much extra harm could be caused by the flavorings, the heating process, problems with safety and quality control with the vaping juice and other issues.