Particulate Matter and Chemicals Attack Your Lungs: The Link Between Environmental Pollution and Chronic Cough

When we translate ‘exterior bound by wind-cold’ and the ‘six excesses’ from Donguibogam into the language of modern science, they correspond to an environmental inflammatory reaction. Modern harmful factors such as particulate matter (PM2.5, PM10), ultrafine particulate matter, volatile organic compounds (VOCs), allergens, and various chemical substances cause direct damage to our lungs and bronchi. When these fine particles enter through the respiratory system, our immune system recognizes them as intruders and mounts a defense. An inflammatory reaction is triggered in this process, damaging airway epithelial cells and excessively activating immune cells, which then secrete inflammatory mediators like cytokines. It is much like a small battle taking place. Such chronic inflammation causes the airway mucosa to swell and induces airway hyperresponsiveness, causing a cough to trigger easily even with minor stimuli. Furthermore, chronic environmental irritation extends beyond a localized lung issue to affect our systemic balance. When sensitive irritant receptors distributed inside the respiratory system are continuously exposed to pollutants, they send excessive signals to the brain through the vagus nerve. This stimulates the cough center in the brain and makes the cough reflex even more sensitive, leading to coughing in response to trivial irritation. In addition, this environmental stress increases the secretion of cortisol, our body's stress hormone. While it suppresses inflammation in the short term, over time it can disrupt the immune system and paradoxically worsen chronic inflammation. When the barrier function of the lungs weakens and ciliary movement decreases, pollutants and viruses penetrate more easily, creating a vicious cycle. Recent studies also report that an imbalance in the lung microbiome influences respiratory conditions such as chronic cough. Although our body constantly interacts with the external environment to maintain balance, modern pollutants can easily disrupt that harmony. Even for a simple cough, attentive observation of your environmental exposure is essential.