Teens vaping more flavored marijuana and less nicotine, study finds UC Davis study: Disposable vapes may be more toxic than cigarettes Disposable vapes in the UK National Centre for Social Research Turns out the disposable nicotine delivery systems are, as suspected, worse than the real thing, according to a new study from researchers at UC Davis. Study: Partial Flavor Ban on Vapes Had Addiction Consequences for American Students UW CTRI UWMadison