Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Grey smog refers to a type of air pollution that is characterized by a mixture of smoke, fog, and industrial pollutants. It is often seen in urban areas with high levels of vehicle emissions and industrial activities.
Particulate matter refers to tiny solid or liquid particles suspended in the air. These particles can come from various sources such as dust, smoke, or vehicle emissions.
Air Quality Index (AQI): AQI is an index used to measure and report daily air quality levels. It provides information about how polluted the air is and helps people understand potential health risks.
Photochemical Smog: Photochemical smog is a type of smog formed when sunlight reacts with pollutants like nitrogen oxides (NOx) and volatile organic compounds (VOCs). It often occurs in sunny cities with high traffic levels.