Fukushima : The Japanese government has issued the evacuation

The average person in North America receives 2000 to 3000 microSieverts of radiation per year. By comparison that is approximately 30 hours in proximity to the Fukushima reactor (<1.5km).

The average CT scan inflicts between 5,000 and 35,000 microSieverts on the body, representing 50 hours or 350 hours in proximity to Fukushima (<1.5km).