Remediation of Bacillus anthracis contamination in the U.S. Department of Justice mail facility

The U.S. Department of Justice (DOJ) mail facility in Landover, Maryland, was contaminated with Bacillus anthracis spores as a result of the 2001 anthrax bioterrorism attacks through the U.S. postal system. Surface environmental sampling within the facility indicated that the contamination was due to receipt of mail that had come in contact with Bacillus anthracis spores from the source letters at the Brentwood postal facility in Washington, DC. The DOJ adopted a two-pronged approach for remediating the facility, using aqueous chlorine dioxide to decontaminate hard, nonporous surfaces and paraformaldehyde to fumigate two pieces of mail equipment. Before the start of the remediation activities, all porous materials were removed from the mail area. Since all postremediation environmental samples were negative for growth of Bacillus anthracis spores, the remediation was judged to be effective. The facility remained closed for almost 4(1/2) months. The cleanup activities took about 2(1/2) months, with source reduction activities being the most time-consuming. Of the seven facilities that performed fumigations to remediate Bacillus anthracis contamination, the DOJ mail facility was the second building to be reopened.