This might be helpful.. or not. From the...
http://lsda.jsc.nasa.gov/books/apollo/S2ch3.htm
BIOMEDICAL RESULTS OF APOLLO
SECTION II
CHAPTER 3
RADIATION PROTECTION AND INSTRUMENTATION
by
J. Vernon Bailey
Lyndon B. Johnson Space Center
(relevant excerpts)
The solar and cosmic radiation found in space has long been recognized as a possible danger in space travel. Exposure to such radiation has the potential of causing serious medical problems. For example, radiation exposure can produce a number of significant changes in various elements of the blood, making an individual more susceptible to disease; also, ionizing radiations of the type found in space can produce significant damage to the lens of the eye. Radiation exposure can also cause temporary or lasting damage to the reproductive system ranging from reduced fertility to permanent sterility. The extent of damage depends upon the tissue involved, the duration of exposure, the dose received, and other factors.
...
Van Allen Belts
The problem of protecting astronauts against the radiation found within the Van Allen belts was recognized before the advent of manned space flight. These two bands of trapped radiation, discovered during the Explorer I flight in 1958, consist principally of protons and high-energy electrons, a significant part of which were, at that time, debris from high-altitude tests of nuclear weapons. The simple solution to protection is to remain under the belts [below an altitude of approximately 556 km (? 300 nautical miles)] when in Earth orbit, and to traverse the belts rapidly on the way to outer space. In reality, the problem is somewhat more complex. The radiation belts vary in altitude over various parts of the Earth and are absent over the north and south magnetic poles. A particularly significant portion of the Van Allen belts is a region known as the South Atlantic anomaly (figure 1). Over the South Atlantic region, the geomagnetic field draws particles closer to the Earth than in other regions of the globe. The orbit inclination of a spacecraft determines the number of passes made per day through this region and, thus, the radiation dose.
Particles within the Van Allen belts, in spiraling around the Earth’s magnetic lines of force, display directionality. This directionality varies continuously in angular relationship to the trajectory of the spacecraft. Therefore, dosimetry instrumentation for use in the Van Allen belts had relatively omnidirectional radiation sensors so that the radiation flux would be measured accurately. The Van Allen belt dosimeter (figure 2) was designed specifically for Apollo dosimetry within these radiation belts.
The rest of the document covers all other forms of possible radiation. Again, it comes down to whether or not you believe NASA. And keep in mind, this collective information about the function of radiation is known data that is used in order to plan satellite trajectories within safe margins of the belt.