Disposable vapes are more toxic than cigarettes, contain lead: Study 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. Vaping tied to increased lead, uranium exposure risk: Research Consumer Vape Products Importance of Shelf Life Studies Vaping While Pregnant? Duke Study Reveals Dangers to Fetal Growth and Development in Mouse Model Duke Health UC Davis study: Disposable vapes may be more toxic than cigarettes