We have little, if any, information for the environment PSP is going to operate in. It is reasonable to expect that the spacecraft will encounter high particle intensities, including elevated numbers of neutrons. The mission total ionizing dose (TID) of radiation is estimated to be 24 krad behind 100 mils (2.54 mm) of Al shielding.
The other concern is interplanetary dust. This is a novel concern for a heliophysics mission because PSP is the first spacecraft to receive dust impacts at a high orbital velocity, about 170 km/s at perihelion at a location where significant amounts of interplanetary dust are thought to be present. Unfortunately, we know little about the dust environment close to the Sun (see discussion in Sect. 1.4). The Helios measurements from 0.7 to 0.3 AU are the only available measurements (Leinert et al. 1981).