There have been rising concerns for troopers that longterm exposure to the radiation may have links to cancer. East Dakota Highway Patrol ordered a ban for hand-held radar guns.

The ban put 70 hand-held radar guns to be withdrawn from service in the Sioux City area as of yesterday.

Adam Smith, the spokesman, said, “The feeling here is to err on the side of caution until we know more about the issue. The situation is under control.”