He pointed to another number, changing as rapidly as the first, but on a lower trajectory; it rose to a high of 8.79 rem per hour. Several lifetimes of dentists’ X-rays, to be sure; but the radiation outside the storm shelter would have been a lethal dose, so they were getting off lightly. Still, the amount flying through the rest of the ship! Billions of particles were penetrating the ship and colliding with the atoms of water and metal they were huddled behind; hundreds of millions were flying between these atoms and then through the atoms of their bodies, touching nothing, as if they were no more than ghosts. Still, thousands were striking atoms of flesh and bone. Most of those collisions were harmless; but in all those thousands, there were in all probability one or two (or three?) in which a chromosome strand was taking a hit, and kinking in the wrong way: and there it was. Tumor initiation, begun with just that typo in the book of the self. And years later, unless the victim's DNA luckily repaired itself, the tumor promotion that was a more or less unavoidable part of living would have its effect, and there would appear a bloom of Something Else inside: cancer. Leukemia, most likely; and, most likely, death.
Kim Stanley Robinson, Red Mars
science, science-fiction