XKCD provides a better radiation chart

Nothing will change at all, even for people who live right next to the plant.

Someone sitting at the front gate of the plant for the past week would have absorbed approximately 100 mSv of radiation. This is a significant amount -- equal to the recommended annual limit for radiation workers -- but too low to cause radiation sickness (symptoms of acute radiation sickness start at between 250 and 500 mSv).

The cancer risk from radiation is roughly 0.01 cancers per Sievert, so this individual would have a 0.1% increase in his chance of getting cancer. People living further away would naturally have even lower probabilities of developing cancer.

Based on the population density of the surrounding area, there is a low probability of any cancers being caused by the Fukushima nuclear incidents, even if the residents had not been evacuated.

(Does this mean that the residents should not have been evacuated? No. It means that the evacuations were a precautionary measure to keep them safe in case the situation got worse than it has in fact gotten.)