In relation to the 2011 Tōhoku earthquake and tsunami , which resulted in multiple nuclear meltdowns and an official Level 7 disaster , officials from W.H.O. and the United Nations have determined that the risks of dangerous exposure are minimal . Nevertheless , scientists and citizens alike remain skeptical . Former nuclear industry executive and whistleblower Dr. Arnold Gundersen and his institute , Fairewinds Associates , tested for the presence of radioactive dust on land scheduled to be used for particular upcoming Olympic events , including men 's baseball , women 's softball , and the traditional Olympic torch run . He found that there were amounts present up to 20 times higher than allowable amounts , as determined by the National Academy of Sciences ' " linear , no-threshold " model
2011 Tōhoku earthquake and tsunami
2011 Tōhoku earthquake and tsunami
2020 Summer Olympics