South Korean regions report rising ozone levels and increased monitoring

Environmental research institutes in Incheon and Chungbuk have released their 2026 ozone monitoring results, highlighting trends in air quality. In Incheon, ozone advisories were issued 40 times over 15 days. While the frequency of advisories remained similar to the previous year, the cumulative average ozone concentration rose by 5.4% through September.

In the Chungbuk region, the ozone warning system operated for seven months from April to October. A total of five advisories were issued across several municipalities, including Chungju, Jeungpyeong, Eumseong, Jincheon, and Goesan. Both regions have implemented stricter standards for lifting advisories, lowering the threshold from 0.12 ppm to 0.10 ppm.

Ozone is a secondary pollutant formed by the photochemical reaction of nitrogen oxides and volatile organic compounds in sunlight. Health officials warn that high concentrations can irritate the eyes and respiratory systems, particularly affecting children, the elderly, and those with pre-existing respiratory conditions. Authorities recommend reducing outdoor activities during high-concentration periods.