[ RadSafe ] Sickening Solar Flare

[Dick Petit]

While I agree that the radiation dose fatal to 50% of humans (LD-50) is not
precisely known, the thing that is being overlooked in comments on the
LD-50 in the NASA article is medical treatment.

300-rads may in fact be the approximate LD-50 without medical intervention,
while 

450-rads is the approximate LD-50 for persons receiving the best medical
treatment, and 

>600-rads has been quoted as the approximate dose level at which virtually
100% of human victims will not survive - even with the best medical
treatment.