Researchers at Imperial College London have discovered a link between climate change and increased incidence of lung problems such as chronic respiratory syndrome.
Professor Fan Chung and Dr David A Edwards have had a hypothesis for years that human airways are a bit like the leaves of plants.
As the planet heats up over time, it gets warmer but also drier, which the researchers found out the lungs are affected in a similar way to plantlife.
Edwards said: “Human airways have a means of remaining hydrated, moist in almost any condition.
“So leaves of plants, even on a dry day, they stay moist and they continue to evaporate water.
“It’s true that a leaf on a very dry day, followed by another dry day by another dry day, eventually wilts and if it’s dry for too long, the plant dies.
“And so what happens in human airways is similar when the air is really dry and hitting our airways, we cough, we get bronchioconstriction.”
Essentially, the more chronic exposure a person has to dry air in the atmosphere, the more likely they are to develop chronic lung problems.
Edwards said: “The airways that are most vulnerable, and it’s particularly on mouth breathing, because we fail to get the humidification that occurs in the nose—these are the larynx, the trachea, and the first generations of your airways down into what we call the bronchioles.”
When the air is too dry, it reduces the amount of mucous and fluid lining the cells on these surfaces, which are called airway epithelial cells.
Chung said: “As you breathe in, you know the air gets through the nose or through the mouth at the back, goes to the back and then hit the larynx, the voice box, right and there, and that opens up the entry into the lungs.
“So the entry into the lungs, there’s a main, main road, which we call a trachea, that divides into two, right and left, and then the right and left divide into further branches.”
What this means is that these epithelial cells are less protected, and therefore, become more easily inflamed.
The evidence for this usually arrives in the form of cytokines, the anti-inflammatory cells which arrive when inflammation occurs in specific places of the body.
One of the biggest signs of chronic respiratory disease is the presence, and then a cascade, of these cytokines.
The team took two groups of mice, one normal and one genetically modified to have dehydrated airway, and exposed them to dry air for 15 minutes twice a day for two weeks.
What they found was the mice with dehydrated airways had much more of these cytokines than the normal mice.
The other way they conducted the experiment was by taking a culture of epithelial throat cells – in laymen’s terms, sticking a cotton swab into a person’s throat, rubbing that cotton swab on a petri dish, and exposing the cells collected on that petri dish to various things, in this case dry air.
This is what Professor Chung referred to as an in-vitro model, and it also showed massively increased cytokines, which meant inflammation.
For those who already suffer lung problems, Chung had some advice.
He said: “One of the ways in which we can rehydrate airways is to inhale nebulised saline salt water, which is used for people with cystic fibrosis, for example.”
Recently-retired lung doctor Sydney Maynes explained he had witnessed an uptick in cases of chronic respiratory syndrome in recent years.
Maynes said: “I actually saw a decline for a while as smoking became less popular with the general public, but now that you mention it, in the past decade or so I did see an uptick.
“And then, of course, there’s Covid.”
Chung also mentioned Covid-19.
He said: “Around about 30-40% of people with long Covid do have a chronic cough, which could be the result of this dehydration and the release of these cytokines.”
It isn’t exactly an optimistic prognosis, but as the planet heats up, each one of us will have to find ways to adapt to increased problems.
Feature image: Public domain
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