Air pollution index refers to the degree of air pollution, the greater the index, the more serious the air pollution; The smaller the index, the better the air quality, which is beneficial to human health. The ways to cause air pollution include industrial pollution, agricultural pollution, the increase in the number of cars, the increase in exhaust emissions, human deforestation, indiscriminate reclamation of grasslands, destruction of vegetation, and increased dust.
So, the answer is: air pollution; Air pollution.