Elevated radiation claimed at Tokyo 2020 Olympic venues

A citizens' group in Tokyo has found elevated levels of radioactivity at sporting facilities that will be used in the 2020 Olympic Games and is warning that competitors and the hundreds of thousands of people expected to flock to the city for the event will be putting themselves in danger.

The Citizens' Group for Measuring Radioactive Environment at Facilities for the 2020 Tokyo Olympics claims wind-borne radiation from the four crippled reactors at the Fukushima nuclear plant has contaminated a number of future venues.

Measurements were taken at 39 sporting venues that have been earmarked to stage events in seven years' time, including the Kasumigaseki Country Club, which will host the golf tournament, the Asaka shooting range and the site of the planned National Stadium, which will stage the opening and closing ceremonies and a number of other events.

The tests were also carried out at the planned site of the Olympic Village and the media centre, with the highest radiation reading - 0.484 microsieverts per hour - detected in undergrowth close to Yumenoshima Stadium, where the equestrian events will be held.

Soil samples collected at the site had 3,040 becquerels of caesium per kilogram.

Some experts point out that the context in which the tests were carried out is crucial.

"It is difficult to have this debate unless we know for sure whether this radiation is from Fukushima or whether it is naturally occurring background radiation," said Pieter Franken, founder of the Japan office of the environmental monitoring organisation Safecast.