Define "smog" in the context of air quality.

The definition of "smog" as a type of air pollution that is a mixture of smoke and fog accurately describes its characteristics and composition. Smog typically arises when smoke from industrial processes or vehicle emissions combines with fog, resulting in a thick, hazy atmosphere. This phenomenon is most prevalent in urban areas where emissions are high, especially during conditions of humidity and low wind. The mixture can contain harmful pollutants, including particulate matter and various chemical compounds, making it a significant concern for air quality and public health.

Understanding smog as a combination of smoke and fog highlights its dual nature as both a byproduct of human activity and a meteorological condition. Smoke contributes pollutants into the air while fog provides the moisture necessary for these particles to coalesce, creating a dense, unhealthy atmosphere. This definition is crucial for grasping the implications of smog on both environmental health and air quality regulations.