Which of the following terms is associated with the loss of trap seals?

The loss of trap seals is primarily associated with siphonage. When water in a trap is effectively "sucked" out due to a difference in pressure, typically caused by a flow of water in nearby pipes or a sudden change in pressure within the drainage system, it results in siphonage. This can lead to the trap's water seal being compromised, allowing gases from the sewer system to enter the living space, which is hazardous.

Siphonage can occur when fixtures are connected to a drainage system with long horizontal runs, or when plumbing vents do not function properly, creating negative pressure situations.

Other factors, while related to plumbing systems, do not specifically refer to the process by which trap seals are lost in the same way. For example, back pressure mainly refers to pressure that pushes against the flow of water, while evaporation involves the loss of water due to temperature conditions, and capillary action describes the movement of water within small spaces without any external forces. These phenomena do not directly relate to the mechanics of trap seal loss as siphonage does.