More than a year after a massive tsunami caused a meltdown at Japan's Fukushima Daiichi nuclear power plant, the World Health Organization says that several areas near the facility had radiation above cancer-causing levels but most of the nation did not.

The UN health agency released its first global estimate Wednesday of radiation exposure from the nuclear disaster caused by the earthquake and tsunami that hit Japan on March 11, 2011. The agency said the increases in radiation that resulted from the meltdown of three reactors at the Fukushima plant were below levels considered cancer-causing in nearly all of Japan.

The agency's 124-page report also says neighbouring countries had levels similar to normal background radiation and people in some other countries had minor exposure through food.

The UN's International Atomic Energy Agency has previously confirmed that radiation levels in some Japanese milk and vegetables reached significantly higher levels than Japan allows for consumption.