DNA Explainer: Here's why air pollution causes long-term coughing

The emergence of stubble-burning season turns the national capital into a chimney. Every year Delhi witnesses a rapid rise in pollution levels. So much so that it shows tangible effects on people.  The dangerous levels of pollution trigger itching in the throat and eyes, and coughing. 

Many doctors have reportedly received complaints from patients regarding prolonged coughing and sneezing. This is actually one of the most common symptoms of high AQI. When something like any gas affects the throat or airways, it results in coughing. 

What is the science behind this air pollution-led prolonged coughing?

Coughs can be long, short, deep or shallow and forced or stifled. A human cough releases assumable three-quarters of a two-litre soda bottle's volume of air. Coughing also lets out many tiny saliva droplets. Cough is an involuntary reflex, a response by our body when things like germs, and dust particles irritate our throat and airways. 

“Pollutants trigger bronchi construction by activating peripheral nerve receptors in the bronchi, causing persistent coughing. Research has shown a significant link between this condition, especially concerning particles with an aerodynamic diameter of less than 2.5 micrometres, commonly referred to as PM 2.5,” said Dr Neetu Jain, Consultant Pulmonology of Critical Care and Sleep Medicine at PSRI Hospital told India Today. 

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When any irritation occurs in the throat, our brain instructs the chest and abdomen muscles to expel air to clear the throat. While occasional coughing is a healthy coping mechanism of the body, prolonged coughing can indicate some underlying illness.  

Dr Jain told India Today, "The exposure to certain gases like sulphur dioxide, ozone and nitrous oxide, which is present in polluted air, is associated with an increase in cough and chest tightness. This establishes a clear link between air pollution and coughing,"

Coughs can occur due to various diseases such as pneumonia, bronchitis, or the flu. However, any of this will be accompanied by some other symptom. It is advisable that in any case, one should consult a doctor and get medical assistance.