Here's my stab at some of the story:
After the anthrax scares in 2001, the USPS purchased eight e-beam machines from SureBeam, a subsidiary of Titan, for about $40 million. As an interim measure they contracted out the irradiation of mail addressed to govenment offices in Washington DC to IBA in New Jersey and Titan in Ohio. All mail from postal facilities where anthrax had been discovered may also have passed through the irradiation equipment as a one-off exercise.
From the March 6, 2002 USPS Emergency Preparedness Plan:
"Intervention, in the form of e-beam irradiation, will continue for all mail being delivered to government offices within the 202 to 205 ZIP Codes. In addition, construction will begin on at least one, and potentially two facilities to house the eight e-beam accelerators purchased as one of the initial response actions. Once construction of these facilities is complete and the e-beam equipment is installed it will be available for continued intervention activities as well as decontamination of mail, should future bioterrorism attacks occur against the Postal Service."
The USPS were still contracting out the irradiation of the mail addressed to Washington DC government offices in October 2003 (by then only the IBA facility in Bridgeport NJ), and the USPS was hoping to have their own facility in DC. The eight USPS machines were still not in use. (Source: USPS press release October 2003). The IBA contract was extended to May 2005, with options until May 2006. (Source; IBA)
That's as much as I've found so far from reliable sources - ie government and supplier websites. Other than using e-beam equipment in the event of an identified occurrence of mail contamination, everything suggests that the only irradiated mail is that destined for government offices in ZIP codes 202 to 205. Does anyone have further information from reliable sources?
Best,
Helen
PS I hope that you will forgive me for calling the government and manufacturers 'reliable sources'.
