[sgath92]

> she's in apartment 349 which is on the third floor. Very hard to imagine off gassing from the ground creates hazardous conditions three floors up.

I don't know enough about VOCs in this context, however, I do know radon problems fairly well and with radon gases released by radioactive decay underground find their way into peoples' basements.

From there, they don't stay in basements. If they did, the risk to humans would be more mild. Instead, the radon gases migrate upward in the building towards the attic exposing everyone in the living quarters along the way.

Attic design is critical to how the radon flows in a house. You could actually increase the amount of radon that flows into a house by having too much attic ventilation along the roof peak. The ideal way to minimize radon involves low-roofline ventilation of the attic combined with trying to seal the basement floor of cracks/holes/etc.

*If* VOCs travel like radon, it would actually make sense that the higher floors will be more affected.