Irradiated DC-bound mail reduced

WASHINGTON (CNN) - The amount of Washington-bound mail that is being irradiated to kill anthrax and other deadly pathogens has declined significantly since the U.S. Postal Service first began zapping mail seven years ago, government auditors told Congress Thursday.

But government offices' ingenuity in finding ways to circumvent the security procedure is partly responsible for the reduction, the Government Accountability Office said.

Some 23,700 containers of mail were irradiated per month in 2002 in the aftermath of the letter-born anthrax attack on Capitol Hill. But only 11,700 containers of mail were being irradiated every month in 2007, the GAO said.