Airborne radiation in Fukushima forests down 57% from FY2011

29 May 2015

Airborne radiation levels at 362 survey points in Fukushima Prefecture’s forest areas averaged 0.39 microsieverts per hour in fiscal 2014, down 57% from 0.91 microsievert in fiscal 2011 logged after the Fukushima Daiichi nuclear power plant disaster, according to the prefectural government's announcement on May 28. It proved once again that radiation in the air is diminishing almost at the same rate as the natural decay of radioactive cesium.

The prefectural government presented the results at a briefing in the city of Fukushima for people involved in the forestry industry. The data showed an average radioactive dosage of 1.07 microsieverts per hour at 134 spots in areas where evacuated residents are allowed temporary visits but no overnight stays due to the contamination.

Since the nuclear disaster, the prefectural government has been monitoring the level of airborne radiation in forests at points 1 meter above ground, except in areas with particularly high dosages where entry is strictly restricted.