Acute Exposure to Environmental Tobacco Smoke: A Controlled Study in Adults with Asthma

Abstract

Background: Short-term, indoor exposure to environmental tobacco smoke (ETS) is still highly prevalent; however, little is known about the acute lung response in adult asthma. Objectives: We investigated whether acute, experimental ETS exposure influences symptoms, lung function, and inflammatory parameters. Methods: Human subjects with asthma (n = 23) were exposed for 180 min to either room air or ETS at 250, 450, or 850 mu g/m(3). Respiratory symptoms, lung function, and exhaled nitric oxide (FeNO) were measured. Additionally, blood samples were analyzed for pro- and anti-inflammatory cytokines. Results: Humans with asthma demonstrate an increase in respiratory symptoms at all levels of ETS exposure, while the forced expiratory volume in 1 s (FEV1) and FeNO decrease with increasing ETS. The anti-inflammatory cytokine interleukin (IL)-10 increases at intermediate ETS concentrations, whereas tumor necrosis factor (TNF)-alpha and IL-8 increase only at the highest ETS concentration. Conclusion: Following 180 min of acute, experimental ETS exposure, we observed a significant increase in respiratory symptoms, a decrease in lung function, and an increase in inflammatory cytokines, indicating an acute lung response in asthma.