The ministry for the first time analyzed the results of physicals reported to a labor standards inspection office which has jurisdiction over 2 nuclear plants in Fukushima.
Some 6,700 people engaged in radiation-related work for 545 work units in the region took special physicals last year.
Most of them are believed to be plant workers.The health ministry officials say that 284 of them, or 4.21% of the employees in the area, showed unhealthy medical readings, such as higher white blood cell counts.
They were required to take more detailed tests or undergo treatment.The proportion of people with health issues was up 3.23 percentage points from the figure reported in 2010, before the nuclear crisis.The ministry says it's not easy to simply compare the results since the work units have seen 70% of their employees replaced over the past 3 years.
But, it says it plans to conduct an epidemiological survey to learn more about the impact of the radiation.
Sep. 20, 2013 - Updated 21:11