Q:

Does orbiting within the outer Van Allen radiation belt increase or reduce environmental radiation levels?

GPS satellites are right in the outer Van Allen radiation belt (a little above 20,000 km). Communications satellites in GEO are higher, but still in it.
If I recall correctly, both the inner and outer Van Allen belts have increased levels of radioactivity and can damage satellites.
So why are there so many satellites in an area which is such a bad place for them to be orbiting in? Is there some major benefit making it all worth it?

A:

The Van Allen belts, while damaging to satellites, aren't fatal to them. Basically, if there's a justifiable reason to orbit at a particular location, then satellites will orbit at that location, even if additional damage could result. The satellites will simply be hardened to take advantage of that. There is a whole slew of factors involved in orbit determination, including some of the following:

Coverage
Launch availability
Time of day on Earth (Earth observing)
Customer locations
Lifetime of satellite.

The bottom line is though, it might add a small amount to protect against additional radiation, but the cost of the satellite won't be drastically more for orbiting in the Van Allen belts.

