The first published study by Japanese researchers found that exposure levels were much lower than those reported after the 1986 nuclear accident at Chernobyl in Ukraine, The Washington Post reported Wednesday.
The Japanese study measured radiation in 8,066 adults and 1,432 children from the town of Minamisoma, some 14 miles north of the Fukushima plant.
They received an average dose of radiation less than 1 millisievert, considered to be a safe amount.
Roy Shore of the Radiation Effects Research Foundation in Hiroshima, Japan, told the Post the dose constitutes a very low health risk.
Background radiation from natural sources such as radon gas is typically around 2 to 3 millisieverts per year.
The study is considered preliminary. It measured only internal radiation from cesium and did not address external radiation from contaminated areas.
Harvard University's David Weinstock attributes the results to the public health response in Japan.
"In Chernobyl, there was no response in the beginning and people were left to consume contaminated food, while in Fukushima the response has been to evacuate and to stop food consumption from contaminated areas, and it seems to have been validated," he said.