1. Very little.
2. No.

Radon gas is not the serious health(serious is actually too intense) issue. The secondary gases that occur when radon decays are the problems.

Most agencies say any adverse health effects from exposure to radon take decades to occur---and the exposure has to be almost daily.

Also, there have been no studies done to prove/pinpoint radon damage. The figures and info have been accumulated through statistics and empirical evidence. In other words, it is an educated guess.

Thanks, it's just scary to read what's on the internet. There could be hundreds of pc/l radon if there's a leakage. But I would imagine the level would be minimal if the air only escaped for a few seconds.

I doubt the amount you released(if any at all) would be measurable.

Radon is greatly over rated---Canada's government is way less concerned about it and they have a high incident of the gas country wide.

Yeah, and I think they allow you to install the fan in the basement, which US doesn't as allow, and I don't understand. If there's a leakage above the fan (positive pressure), it would be a problem