annex a of the unscear (united nations scientific committee for the effects of atomic radiation) 2013 report to the un general assembly states that the average effective dose of the 25,000 workers over the first 19 months after the accident was about 12 millisieverts (msv). about 0.7% of the workforce received doses of more than 100 msv (chapter ii a(b) paragraph 35). no radiation-related deaths or acute diseases have been observed among the workers and general public exposed to radiation from the accident (chapter ii a(b) paragraph 38). adults living in the city of fukushima were estimated to have received, on average, an effective dose of about 4 msv (chapter ii a(a) paragraph 30). no discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants (chapter ii a(b) paragraph 39). average annual exposure in the region from naturally occurring sources is about 2.1 msv, and average lifetime exposure is 170 msv (chapter ii a(2) paragraph 29). for comparison, the average dose from an abdominal and pelvic computed tomography (ct) scan, with and without contrast, is 20 to 30 msv.