Giant database captures fluctuating radioactivity levels in vegetables, fruit, meat and tea.
27 February 2015
A massive food-monitoring programme in the wake of the Fukushima nuclear disaster has provided scientists with a unique look at how radioactivity peaks in different foods after a nuclear spill.
Almost four years since the incident, the first analysis of the data also confirms what multiple studies of Fukushima residents have already shown: few people are likely to have eaten food that exceeded strict Japanese limits on radioactive contamination.
On 11 March 2011, a massive offshore earthquake triggered a tsunami that swamped the Fukushima Daiichi nuclear power station. Plumes of gas from the reactor released radioactive isotopes into the local area, which were transported farther afield by wind and rain, before falling onto plants and seeping into soil.
The Japanese government banned products that were likely to have been affected, including leafy vegetables, which can absorb radioactive elements through their leaves, and milk from animals that had been feeding on local grass.
The government also instigated an extensive monitoring campaign, sampling foods before they hit the market for levels of radioactive elements such as caesium-137, and banning producers or areas that exceeded regulatory limits.