Levels of radioactivity, in a radius of 80 km (50 miles), around the Fukushima nuclear plant have gone down by 65 percent since the nuclear disaster in March 2011, Japanese authorities announced on Thursday.
The data, collected by the Nuclear Regulation Authority (NRA) show a significant decrease in radiation in areas closest to the plant, owing to the decontamination work carried out over the last five years, EFE news reported.
Areas affected by higher levels of radiation (above 19 microsieverts per hour), northwest of the station, have reduced considerably from the first month after the accident till the last measurement in early November.
Radiation levels also decreased in areas which recorded levels between 0.1 and 1.9 microsieverts, in localities south of Miyagi and Fukushima prefectures and to the north of the neighbouring Ibaraki, according to the NRA report.
The Japanese nuclear regulator collected this data from radiation measurements carried out by helicopters at a height of one meter (3.2 feet) above the ground.
After the nuclear accident, triggered by an earthquake and a tsunami on March 11, 2011, the Japanese government ordered total or partial evacuation of eight municipalities situated at distances of up to 30 km from the nuclear power plant and since then around 70,000 people have been unable to return to their homes.
The Fukushima disaster is considered the worst nuclear accident, since Ukraine's Chernobyl in 1986, whose emissions and discharges also severely affected local farming, cattle-raising and fishing.