VIENNA - The Fukushima nuclear disaster is unlikely to lead to a rise in people developing cancer as happened after Chernobyl in 1986, even though the most exposed children may face an increased risk, U.N. scientists said Wednesday.
In a major study, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) said it did not expect “significant changes” in future cancer rates that could be attributed to radiation exposure from the reactor meltdowns.
The amounts of radioactive substances such as iodine-131 released after the 2011 accident were much lower than after Chernobyl, and Japanese authorities also took action to protect people living near the stricken plant, including evacuations.
However, some children — estimated at fewer than 1,000 — might have received doses that could affect their risk of developing thyroid cancer later in life, UNSCEAR said, while emphasizing the probability of that happening was still low.
UNSCEAR chairman Carl-Magnus Larsson said there was a theoretical increased risk among the most exposed children for this type of cancer, which is rare among the young.
But “we are not sure that this is going to be something that will be captured in the thyroid cancer statistics in future,” he told a news conference.
Wolfgang Weiss, who chaired the Fukushima assessment, said the thyroid cancer risk was much lower compared with Chernobyl and any increase would be limited.
On March 11, 2011, the magnitude-9 earthquake and tsunami devastated the Fukushima No. 1 nuclear plant in Fukushima Prefecture, spewing radiation and forcing about 160,000 people to flee their homes.
It was the world’s worst nuclear disaster since the Chernobyl reactor explosion sent radioactive dust across much of Europe. People close to the then-Soviet plant were exposed to radioactive iodine that contaminated milk and radiation that turned surrounding areas into ghost towns for decades.
In contrast, UNSCEAR’s Fukushima report said it expected a low impact on cancer rates for the population and that this was largely due to “prompt protective actions” after the meltdowns.
A 30-km radius around the plant was eventually declared a no-go zone, while areas where radiation was not so critically high took steps such as replacing or turning over earth in parks and playgrounds, decontaminating public spaces and limiting children’s outdoor play time.
“No discernible changes in future cancer rates and hereditary diseases are expected due to exposure to radiation as a result of the Fukushima nuclear accident,” UNSCEAR said in a statement accompanying its nearly 300-page study.
The thyroid — a gland in the neck that produces hormones that regulate vital bodily functions — is the most exposed organ because radioactive iodine concentrates there. Children are deemed especially vulnerable.
UNSCEAR said the normal thyroid cancer risk for children was very low.
“The occurrence of a large number of radiation-induced thyroid cancers as were observed after Chernobyl can be discounted because doses were substantially lower,” it said.
In Belarus, Russia and Ukraine, the countries most affected by Chernobyl, more than 6,000 cases of thyroid cancer had been reported by 2005 in children and adolescents who were exposed during the disaster, UNSCEAR says on its website.