High humidity exposures and mechanisms in respiratory disease

Over the past five decades, anthropogenic activities have precipitated a sustained rise in global temperatures. This warming trend enhances the atmosphere's water-holding capacity, thereby elevating atmospheric humidity levels. Prolonged exposure to high humidity (HH) adversely impacts nearly all organ systems are increasingly being recognized. As the respiratory system interfaces directly with atmospheric conditions, HH exposure exerts immediate pathological effects on pulmonary structures and functions. The past decades in environmental medicine research have been characterised by a greater understanding of HH to respiratory disease. This Seminar reviews the impact of HH on a spectrum of prevalent respiratory disorders, with an emphasis on respiratory infectious diseases, chronic ventilatory dysfunction, allergic airway diseases, and particulate matter-induced lung injury.