Smog is a type of air pollution that is created when smoke and fog mix together. It is a combination of both natural and man-made pollutants, such as sulfur dioxide, nitrogen oxides, and particulate matter. SMOG can cause a variety of health problems, including respiratory illnesses, eye irritation, and headaches. It can also reduce visibility and create an unpleasant odor. SMOG is a major environmental concern in many cities around the world, and efforts are being made to reduce its impact.