WHO estimates the increased cancer risk of people living inside the Fukushima Prefecture as being up to 70% higher (thyroid cancer for girls exposed as infants)[1]. Numerous other studies indicate increased cancer risk[2].
During the Fukushima meltdown, radiation levels of 3–170 μSv/h (= 17 mrem/hour) were measured within 30 km of the reactor[2]. Safe levels are 5000 mrem/year[3].
As I understand it, many argue that these of cancer risk estimates are high. I'll be happy to change my mind once medical scientist working in the field change theirs.
[1] http://www.reuters.com/article/2013/02/28/us-japan-nuclear-c...
[2] https://en.wikipedia.org/wiki/Radiation_effects_from_the_Fuk...
[3] http://www.nrc.gov/about-nrc/radiation/health-effects/info.h...