signeti
I'm not sure why people think there is a "low level of research", thers's a stack, but most of it is inconclusive, perhaps because the effects are not as great as we think? The comparison between chest X-Ray dosages and flight dosages comes up a lot but the dose rates are vastly different, and it's the rate, more than the total dose that does a lot of the damage. ( btw you can sit in a house in a granite rich area of the world and receive the equivalent of several chest X-Rays a year)
For the Solar flare "fans", flares produce big spikes in the radiation level but the main contributor to the radiation we get is the background Cosmic Radiation (which doesn''t come from the Sun, so much for the accuracy of ther report from "The Age")...and interestingly ( or perhaps not ) when the Sun is at the minimum of it's 11 year activity cycle ( which it is now), and flares are at their most infrequent, Cosmic Radiation is at it's peak..
IMHO there are more important health factors to consider in this job , such as oil fumes, disrupted sleep,irregular exposure to sunlight and as somebody else has mentioned, airline food, if people insist on worrying about radiation, they should worry about Ultraviolet radiation
Regards