Tired light and GBR

The mainstream idea is (I think) light is red shifted by the expansion of the Universe and red light photons has less energy than blue light and lots less energy than gamma photons. A few experts have postulated a tired light theory to explain red shift without an expanding universe, but I believe this has zero main stream acceptance.
So light orbiting the black hole near the event horizon would not loose energy, but it would be absorbed and re-radiated by particles which are also orbiting at nearly the speed of light. This would possibly lead to a loss of energy and red shifting.

I had the impression that only about one millionth of the gamma radiation energy falling on Earth gets though the atmosphere to reach sea level, so extremely large gamma flux is needed to be lethal at sea level, so only near by GRB = gamma ray bursters are dangerous to humans. Please comment refute or embellish. Neil