Thousands still at risk of death according to first estimate of Fukushima worldwide health impacts

Thousands of people could still die as a result of the Fukushima nuclear accident, according to the first estimate of the disaster's worldwide impact.

Scientists found that inhalation exposure, external exposure and ingestion exposure of the public to radioactivity may result in up to 1,300 cancer mortalities and up to 2,500 cancer morbidities worldwide, mostly in Japan.

Their research is published in the latest edition of the Royal Society of Chemistry journal Energy & Environmental Science.

John Hoeve and Mark Jacobson, from Stanford University, said with "modest to major radionuclide releases occurring in almost 1.5% of all reactors ever built", and the worst occurring at Three Mile Island in 1979, Saint-Laurent in 1980 and Chernobyl in 186 prior to Fukushima, "the risk of a meltdown is not small".

They said deaths relating to Fukushima "may be less than Chernobyl . due to a lower total emission of radioactivity, lower radioactivity deposition rates over land and more precautionary measures taken immediately following the Fukushima accident."

Health effects from the fallout are estimated to result in 130 cancer-related mortalities and 180 cancer-related morbidities worldwide. Sensitivities to emission rates and other factors could see those estimates increase to 160 for best estimates and 1,300 for "upper bound estimates".

The researchers add: "Yet due to the substantial uncertainty in the cancer risk from low-dose radiation, the actual number of cancer-related mortalities and morbidities may still fall outside the confidence intervals reported here."

Estimates in the paper do not account for the increased radiation risk to the roughly 20,000 workers at the plant in the months following the accident.

Psychological effects such as those that occurred post-Chernobyl, such as depression, anxiety, fear and unexplained physical symptoms, are likely to be repeated in evacuees after Fukushima. 

"Preventative actions taken by the Japanese government after Fukushima may have reduced radiological health impacts substantially," the authors say, citing the distribution of iodine tablets to people in evacuation centres as one positive example in tackling potential thyroid cancer.

"The number of projected mortalities, however, is still considerably smaller than the nearly 20,000 mortalities from the Tohoku earthquake and tsunami and is also smaller than the estimated number of projected mortalities from the Chernobyl nuclear accident."

The authors concluded: "Because of the significant number of current nuclear power plants and their potential increase in the future, quantification of the health impacts from Fukushima is important.

"The risks and consequences of a meltdown must be considered along with other impacts, risks, costs and benefits of nuclear power in comparison with other electric power sources in deciding the future direction of worldwide policy."

Nobel Prize winning American physicist Burton Richter commented on the paper, also published in Energy & Environmental Science, saying that health effects in Japan would have been "much worse with fossil fuel used to generate the same amount of electricity as was nuclear generated".

Dr Richter added: "It seems that clear that considering only the electricity generated by the Fukushima plant, nuclear is much less damaging to health than coal and somewhat better than gas even after including (Fukushima).

"If nuclear power had never been deployed in Japan the effects on the public would have been much worse."