In a house with forced air heating and cooling, radon gas can quickly be distributed throughout the entire dwelling. When radon gas is released through a radon mitigation system over the roofing system, the radon concentration diminishes significantly with distance from the point of discharge. In fact, the radon gas focus approaches history degrees at 3-4 feet from the discharge factor. EPA refused ground degree discharge of radon mostly because of the potential for re-entrainment of the gas right into your home and also as a result of the opportunity of children being subjected to high radon levels. The concentration of radon gas at the discharge point can be 10s of countless picocuries per minute.