What is the primary factor affecting atmospheric dispersion of pollutants?

The primary factor affecting the atmospheric dispersion of pollutants is wind speed and direction. Wind plays a critical role in determining how pollutants spread away from their source. A higher wind speed generally increases the rate at which pollutants are diluted and transported, reducing their concentration at any given point downwind. Wind direction is also vital; it influences the pathway pollutants take as they move through the atmosphere, impacting which areas might be affected by the pollution.

In addition to wind, while temperature, humidity, and pressure can influence the behavior of pollutants and the overall atmospheric stability, they do not directly control the dispersal process in the same essential way that wind does. For instance, temperature can impact the stability of the atmosphere, impacting vertical mixing, but it is the wind that ultimately drives the lateral dispersion of airborne pollutants.