SAChE Atmospheric Dispersion Practice Test

The height of an emission source plays a significant role in the dispersion of pollutants in the atmosphere. When emissions are released from a higher vantage point, they are able to enter a less turbulent layer of the atmosphere more quickly. This allows the pollutants to spread out more effectively and dilutes them over a larger volume of air, which generally results in lower ground-level concentrations of the pollutants.

Higher sources facilitate better mixing with ambient air, allowing plumes to disperse over a broader area rather than concentrating at lower altitudes where the potential for ground-level impacts is much greater. This phenomenon is especially important in urban areas or environments where ground-level concentrations can pose significant health risks.

In contrast, lower sources often release pollutants closer to the surface, which can lead to higher concentrations at ground level, increasing the likelihood of air quality issues.