The single sickness confirmed by the International Atomic Energy Agency to have been caused by low-dose radiation from Chernobyl is thyroid cancer, which if properly treated with surgery is rarely fatal. Sugenoya, a thyroid specialist, volunteered to work in Belarus, close to the Ukraine power plant, in 1991 after hearing about thousands of cases of thyroid cancer there.
Five years later, he quit his job at a prestigious Japanese hospital and returned for another five and a half years. He has set up a donation fund for Chernobyl victims and regularly brings doctors from Belarus into Japan for training.
It's unclear how the radiation leaks near Fukushima Dai-ichi compare with those from Chernobyl. Measuring exposure at the individual level involves complex calculations to account for the daily intake of food and water, and can vary greatly.
The Japanese government has detected 44 confirmed and suspected cases of thyroid cancer among 217,000 youngsters, 18 and under, checked in Fukushima prefecture (state). Thyroid cancer among children is generally rare, estimated at only one in a million. The link to radiation is still inconclusive, and extensive testing of Fukushima children could account for the higher numbers.
