Vein: A blood vessel that carries blood that is low in oxygen content from the body back t... See the entire definition of Vein Viral: Of or pertaining to a virus.
This means that breathing low concentrations of freon from a leaking refrigerator or air conditioner over a long period of time is unlikely to have a cumulative effect, and thus few, if any, long term health effects.
In freezers, Freon helps keep food cold and temperatures cool or below freezing. If your freezer is working properly, the West Virginia University Extension notes that your temperature should hover around zero F. If your temperature is higher, it can be an indication your freezer is leaking Freon.