The article discusses how air pollutants like SO2, particulate matter, NO2, and others are removed from the atmosphere through processes like rain and washout. The researchers reviewed methods to estimate how these pollutants deposit onto the ground and water surfaces. They also looked at the inventory of pollutants in different regions, how long they stay in the air, and their impact on diffusion models. Key findings include the importance of considering pollutant deposition in long-range transportation and the effects of pollutants on the environment.