https://www.atsjournals.org/doi/full/10.1513/AnnalsATS.201212-127FRSmoking a single tobacco cigarette causes a modest degree of acute bronchoconstriction, which has been attributed to an irritant effect of the smoke leading to cholinergically mediated reflex bronchospasm (4). In contrast, smoking a single “joint” of marijuana (7 mg/kg) containing 2% THC by weight caused acute bronchodilation