Data is scare on radiation coming from Japan 's nuclear reactors . Experts need good practice in building computer models to track radioactivity . Official : ` ` There 's a lot of genuine confusion about what is going on '' Experts say radiation from Japan does not pose a significant health risk to the U.S .
Data is scare on radioactivity coming from Japan 's damaged reactors . Experts need good data in building computer models to track radioactivity . Official : `` There 's a lot of genuine confusion about what is going on '' Experts say radiation from Japan does not pose a significant health threat to the U.S .