February 24th, 2014
04:15 PM ET
The safety measures imposed after the 2011 meltdowns at Japan's Fukushima Daiichi nuclear power plant appear to have averted widespread health risks to the surrounding population, Japanese scientists say.
People who live on the outskirts of the evacuation zone surrounding the plant received only slightly more radiation than normal background doses in the year following the world's second-worst nuclear accident, researchers at Kyoto University concluded. The study indicates that the fallout from the crippled plant presents little hazard to those outside the closed zone, even in towns along its edges.
"In conclusion, food supply and associated regulations are considered effective in the study areas in Fukushima thus far, and external exposure is a major component of the radiation dose rate," the researchers found.
In the three towns that were the subject of the study, radioactive cesium left behind by the disaster is likely to raise the lifetime risk of cancer by about 1%, the researchers reported, a level "which is unlikely to be epidemiologically detectable."
"The lifetime excess risk is small compared with the baseline risk of the Japanese population," the study concluded.
The findings were released online early Tuesday (3 p.m. ET Monday ) in the U.S. scientific journal Proceedings of the National Academy of Sciences.
Three reactors at the Fukushima Daiichi power plant melted down in the wake of the massive earthquake and tsunami that struck eastern Japan in March 2011. The resulting fallout forced nearly 140,000 people from their homes, with only a small number allowed to return so far.
The Kyoto team tracked radiation exposures from the surrounding environment and from food consumption in three still-inhabited towns near Fukushima Daiichi, where the earthquake and tsunami triggered the world's second-worst nuclear accident.
About 460 residents of those towns wore radiation dosimeters for two months, in August and September of 2012, for the study. The researchers also studied the food consumption of 125 people, most of whom ate home-grown vegetables.
But they added one cautionary note; several people who worked in the surrounding woodlands had higher radiation doses over the course of the study.
"Because the neighboring forest is a major economic resource, rigorous external radiation monitoring is needed for residents who routinely work in the forest," it added.
The study was published as Japanese authorities announced they would allow about 350 people from one of the evacuated towns to return home permanently. Another 31,000 people could eventually return home, the government added.
In March 2013, the World Health Organization found any increase in illness was "likely to remain below detectable levels." The gradual unfolding of the calamity gave Japanese authorities time to evacuate many of the surrounding towns before they received high doses of radiation. In addition, many of those residents had already fled the destruction unleashed by the earthquake and tsunami that triggered the Fukushima Daiichi meltdowns, the WHO noted.
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