Dilution or mixing of air pollutants into the surrounding air is best when:
A) winds are calm to light.
B) air is unstable.
C) relative humidity is high.
D) inversions are present.
E) air is very cold.

Question

Quizplus · Accepted Answer

When the air is unstable, it means that there is vertical mixing of air. This helps in diluting or mixing the air pollutants into the surrounding air. When winds are calm, pollutants can accumulate over a specific area leading to higher pollutant concentration. High relative humidity may lead to condensation of pollutants which can further affect air quality. The presence of inversions can lead to trapping of pollutants under a layer of warm air. Very cold air may reduce dilution or mixing of pollutants.

Dilution or Mixing of Air Pollutants into the Surrounding Air