Chengdu, the capital of Sichuan Province, experiences significant air pollution challenges, though conditions have shown a trend of gradual improvement over the last decade. The city’s location within the Sichuan Basin creates a geographical trap that frequently leads to the accumulation of smog, particularly during the winter months from November to March when a persistent layer of cloud and fog prevents pollutants from dispersing. During these peak periods, the Air Quality Index (AQI) often reaches levels classified as Poor or Unhealthy, sometimes exceeding 150 or 200, which can cause respiratory irritation and is particularly hazardous for sensitive groups. Major pollutants include PM2.5, PM10, and ground-level ozone, with the air quality often described as being as harmful as smoking over a cigarette a day. However, the city has implemented massive environmental efforts since 2013, leading to more frequent "blue sky days" in the spring and summer when the air is generally more breathable. Despite these improvements, Chengdu frequently ranks among the most polluted cities globally, and residents often rely on air purifiers and limited outdoor activity during high-pollution alerts.