Since the public understand the difference between fog and haze, people talk about PM2.5 and become pale, and the circle of friends has recently been “mainly depends on the temperament” screen. While flirting, it also reflects the public’s concern for their own health. As a thoracic surgeon, every day surgery can see many patients’ lungs, the impact of atmospheric pollution on the lungs have a more intuitive understanding. PM2.5 and other dust enter the alveoli through the respiratory tract and are engulfed by macrophages (a type of immune cell) in the lung tissue, and the dust-engulfing macrophages become dust cells, some of which are finally excreted with sputum. The more black streaks seen on the surface of the lung tissue, the more dust cells in the lung and the more dust (PM2.5) deposited in the lung tissue, indirectly reflecting the air pollution in the patient’s living environment. Urban residents have significantly more black streaks in their lung tissue than rural residents. At present, haze has been listed as a class I carcinogen, and the treatment of air pollution has reached the point of no delay.