The effect of climate change on respiratory health is the subject of a new study by Imperial College London, in collaboration with researchers at Johns Hopkins University and the University of Carolina.
It examined the level to which dehydrated air triggers airway inflammation and immune responses, with implications for those with conditions such as asthma, chronic bronchitis, allergic rhinitis, and chronic cough.
Using a climate model study conducted as part of the project, the researchers said that they expect most of the population of the continental United States to be at higher risk of airway inflammation by the latter half of this century, due to a combination of higher temperatures and drier air.
Vapour pressure deficit
Vapour pressure deficit (VPD), a measure of how ‘thirsty’ air can be, is expected to rise due to global warming, in turn leading to dehydration of the mucous surfaces in human airways, activating inflammatory and immune responses.
“We have identified that VPD is a major element that causes these problems and will be much more important as the temperature goes up in drier conditions,” commented Professor Fan Chung of Imperial’s National Heart and Lung Institute.
“We believe this will be one mechanism by which climate change will provoke the onset of various respiratory conditions and diseases.”
As the study found, human bronchial epithelial cells exposed to high VPD conditions released large amounts of cytokines, proteins that are ‘potent in causing inflammation of the airways and activating immune cells’, the researchers said. Similarly, genetically modified mice unable to hydrate their airways exhibited increased tissue damage and immune system changes when subjected to dry air.
Rehydrating airways
“More research is needed to determine why some individuals are more prone to the effects of airway dehydration,” Professor Chung added. “And we urgently need to find successful ways to rehydrate individual airways, whether that is by behaviour change, sprays or other therapies.”
The study was published in the Communications Earth & Environment journal. Other research partners included Boston University, Illinois Institute of Technology, and Sensory Cloud Inc. Read more here and here.
