Had their life span been affected by the ambient radiation?

The atmosphere was indeed virtually free of all but natural ambient radiation.

Our own technology is improving too, as you might imagine, and we're getting better at analyzing ambient and background radiation than we used to be.

Not until we work out a technology to shield against the ambient radiation.

"Now we know where that ambient radiation came from."

Lights high above flared red while the computer's voice reported constant rises in ambient radiation.

And we already know it can handle the ambient radiation, although don't ask me how.

In the ocean, of course, they were shielded from the ambient radiation.

Most scanners of this type detect visible light because it is a readily available ambient radiation.

In theory, the ambient radiation should decrease steadily the farther we travel away from the galactic center.