smog

This term describes a specific atmospheric condition where pollutants create a visible, oppressive haze. It carries a strong negative connotation associated with industrial decay, urban congestion, and respiratory health hazards. It is typically used in environmental and journalistic contexts to describe the air quality of large metropolitan areas. As an uncountable noun, smog cannot be pluralized or counted with numbers. To refer to a specific instance or a particular concentration of the pollution, speakers must use partitive phrases such as a layer of smog or a blanket of smog.