TOKYO. Feb 1: Japan raised its estimate of how many people were exposed to radiation In the country's worst nuclear accident to 439 from 70. officials said today, reports Reuters.

September's accident, wnlch killed one person, was triggered when workers put nearly eight times the proper amount of condensed uranium into a mixing tank at a processing plant in Tokaimura, about 140 km northeast of Tokyo.

An official of the Science and Technology Agency, which released the figures, said the calculation took Into account local residents as well as plant workers who were not equipped with radiation monitoring devices at the time of the acclaenL

This makes the number look bigger than the Initial figures we reported," he said.

Of those affected. 207 were local people who lived and worked within a 350 metre radius of the plant. The rest were workers at the plant or those involved in the rescue mission.

Only three had been exposed fo levels of radiation sufficient to cause after-effects and one of the three has already died.

Police last month Inspected the site of the accident, continuing a criminal investigation Into the plant's operators and its parent company.