On 11 March 2011, a massive earthquake and subsequent tsunami struck Japan, leading to a nuclear disaster at the Fukushima Daiichi nuclear power plant. This disaster resulted in the loss of approximately 20,000 lives and the evacuation of over 110,000 residents, many of whom were resettled in Date City. In 2015, the city of Date requested a researcher from Fukushima Medical University to analyse the radiation exposure data that city officials had collected over the years. Problems with informed consent led to the later retraction of relevant articles.