What is the direction of air movement concerning pressure?

Air movement is primarily driven by differences in air pressure, with air always moving from areas of higher pressure to areas of lower pressure. This outward flow occurs because nature tends to favor equilibrium, seeking to equalize pressure differences across the environment. When air moves from high to low pressure, it results in the natural ventilation and circulation essential for various systems, including those in buildings and surrounding areas.

In respiratory contexts or radon mitigation, understanding this movement is critical, as it can influence how radon gas enters and escapes buildings. When mitigating radon, the goal is often to reduce the pressure in the foundation of a building, creating a situation where the air and any contained radon move away from the higher pressure within the building and transition toward lower pressure areas, either indoors or outdoors.

The other options describe air movement inaccurately according to the fundamental principles of fluid dynamics and atmospheric science.