What fine dust can do to your body

Clear skies have returned after days of heavy pollution, but experts warn that the danger of fine dust lingers, often in ways not immediately visible.

Fine dust remains one of the most persistent health threats during Korea’s spring season, with growing evidence that its impact extends far beyond the lungs.

According to medical experts, the health effects of airborne particles vary significantly depending on their size. Larger particles primarily irritate the eyes, nose and throat, but as particles become smaller, they travel deeper into the respiratory system.

Ultrafine particles known as PM2.5 can penetrate all the way to the alveoli, the tiny sacs in the lungs responsible for oxygen exchange, where they can cause direct tissue damage.

Fine dust is particularly dangerous not because it accumulates in the body, but because it attacks it in multiple ways.

Harmful substances such as heavy metals attached to the particle's surface can trigger oxidative stress in lung tissue. This process activates immune cells, leading to inflammation such as swelling and irritation.

Once this inflammation begins, it does not remain confined to the lungs. Instead, the inflammatory response can spread throughout the body, affecting the heart, blood vessels and even the brain. Some studies have suggested that ultrafine particles may enter the bloodstream and circulate systemically.

Because of these mechanisms, fine dust is closely associated with a wide range of illnesses. Even short-term exposure can worsen asthma or other breathing issues and raise the risk of respiratory infections such as pneumonia.

Long-term exposure is known to increase the likelihood of developing lung cancer, and fine dust is classified as a Group 1 carcinogen by the International Agency for Research on Cancer.

Fine dust exposure can also aggravate heart disease and increase the risk of conditions such as high blood pressure and stroke. It has also been linked to heart failure and irregular heartbeats.

More recently, attention has turned to its impact on the brain. Long-term exposure to ultrafine particles may heighten systemic inflammation, increasing the risk of depression. Research continues to explore links to degenerative neurological disorders such as dementia and Parkinson’s disease.

Pregnant women, infants and other vulnerable groups require particular caution. Exposure during pregnancy can increase the risk of preterm birth or low birth weight. In infants and young children, fine dust can hinder lung development, reduce cognitive function and raise the likelihood of developmental disorders.

Health experts advise minimizing outdoor activities on days when pollution levels are high and wearing certified protective masks when going outside. Washing hands and face thoroughly after returning home and keeping indoor air clean are also recommended.