Due to the lack of production oversight, most consumers do not know what is in the e-cigarettes they buy. “Nicotine delivered by any mechanism represents a drug exposure,” said the American College of Allergy, Asthma and Immunology (ACAAI) statement.Inhaling irritants such as smoke and vapours has an impact on the lungs, whether it is mild or severe. And irritants can cause asthma attacks in some individuals, said the study published in the journal Annals of Allergy, Asthma & Immunology.