City blight is a term used to describe the negative effects of urbanization on a city. It is characterized by environmental pollution, such as SMOG, and the presence of slums. SMOG is a type of air pollution caused by the burning of fossil fuels, which results in a thick, visible haze. Slums are areas of a city characterized by overcrowding, poverty, and inadequate housing. Together, SMOG and slums are two of the most common indicators of city blight.